European Journal of General Practice
ISSN: 1381-4788 (Print) 1751-1402 (Online) Journal homepage: http://www.tandfonline.com/loi/igen20
Postoperative abdominal adhesions and bowel obstruction. A survey among Dutch general practitioners Raymond MFM Leclercq, Kevin WY Van Barneveld, Marc HF Schreinemacher, Roxanne Assies, Mascha Twellaar, Nicole D Bouvy & Jean WM Muris To cite this article: Raymond MFM Leclercq, Kevin WY Van Barneveld, Marc HF Schreinemacher, Roxanne Assies, Mascha Twellaar, Nicole D Bouvy & Jean WM Muris (2015) Postoperative abdominal adhesions and bowel obstruction. A survey among Dutch general practitioners, European Journal of General Practice, 21:3, 176-182, DOI: 10.3109/13814788.2015.1055466 To link to this article: http://dx.doi.org/10.3109/13814788.2015.1055466
Published online: 10 Jul 2015.
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Date: 05 October 2015, At: 23:41
European Journal of General Practice, 2015; 21: 176–182
Original Article
Postoperative abdominal adhesions and bowel obstruction. A survey among Dutch general practitioners
Downloaded by [University of Otago] at 23:41 05 October 2015
Raymond MFM Leclercq1, Kevin WY Van Barneveld 2, Marc HF Schreinemacher2, Roxanne Assies2, Mascha Twellaar 1, Nicole D Bouvy2 & Jean WM Muris1 1Department of Family Medicine, CAPHRI School for Public Health and Primary Care, Maastricht University, Maastricht, the Netherlands, 2Department of General Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, the Netherlands
KEY MESSAGE: • • •
GPs believe that bowel malignancy, faecal impaction, adhesions and diverticulitis are the most frequent causes of bowel obstruction. Most GPs differentiate adhesion-related complaints from IBS, in reverse specific patients are difficult to identify. Half of the GPs educate patients about obstructive bowel complaints, more than half advise laxatives, extra fluid and fibres.
ABSTRACT Background: There is increasing interest among specialists in the complications after abdominal surgery due to adhesions. Objective: Exploration of experiences, attitudes and expectations of general practitioners concerning bowel obstruction and postoperative abdominal adhesions. Methods: In October 2012 a postal questionnaire was sent to a random sample of 800 Dutch GPs. Results: The response rate was 45%, 24% (n ⫽ 190) filled out the questionnaire completely, 12% (n ⫽ 99) had no experience with the subject and 7% (n ⫽ 57) had no time to respond. A history of abdominal surgery does play a part in more than 80% of GP’s differential diagnosis of abdominal complaints. Seventy-five per cent consider some types of surgery to induce more adhesions. Eighty-five per cent ponder the differentiation between adhesion related complaints and IBS as clear, however difficult (78%) in specific patients. Intestinal transit problems likely due to adhesions are treated with extra fluid (n ⫽ 64), more fibres (n ⫽ 85) and laxatives (n ⫽ 153). Referral to a specialist for adhesiolysis is rarely considered (11%). Forty per cent of the GPs would refer a patient with abdominal pain and suspected adhesions. Seventy-six per cent denote knowledge gaps and low experience in the treatment of intestinal transit problems. Some (n ⫽ 23) indicate the need for information about adhesions and obstruction through CME papers. Conclusion: Respondents are well equipped to deal with abdominal complaints and intestinal transit problems due to postoperative adhesions. Some indicate the need for information about adhesions and prevention of obstruction through CME papers.
Keywords: Intestinal obstruction, adhesions, surgery-induced, postal survey, general practice
INTRODUCTION In general practice, essential dimensions are personal, continuous and integrated care. These dimensions can be compromised with the existence of rare conditions, such as bowel obstruction and postoperative adhesions. The interest in postoperative adhesions lies especially with
surgeons and gynaecologists and is sometimes found among general practice researchers, making this iatrogenic condition a multidisciplinary issue. One result of this interest is the establishment of the Bologna guidelines for surgeons (1). These guidelines debate the prevention and treatment of postoperative adhesions and their consequences.
Correspondence: Raymond M. F. M. Leclercq, Dept. Family Medicine, PO Box 616, 6200 MD Maastricht, The Netherlands. Fax: ⫹ 31 43 3619344. E-mail: rmfm.leclercq@ maastrichtuniversity.nl (Received 15 October 2013; revised 24 April 2015; accepted 9 May 2015) ISSN 1381-4788 print/ISSN 1751-1402 online © 2015 Informa Healthcare DOI: 10.3109/13814788.2015.1055466
Postoperative adhesions and bowel obstruction
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Operations induce adhesions Per year at least 70 abdominal operations per 10 000 citizens in the Netherlands are being performed (http:// statline.cbs.nl). It is estimated that adhesions arise after 94% of abdominal operations (2). Bowel obstruction due to postoperative adhesions does occur in 2.4% of patients per year after surgery (3). The overall incidence rates for bowel obstructions and ileus in the Netherlands was eleven per 10 000 citizens in 2012 (http://statline.cbs. nl). Implemented into the daily practice, the GP will be confronted with at least three episodes of bowel obstruction per year. The proportion of adhesion-induced bowel obstruction is 2.4% of all abdominal operations and is equivalent with an incidence of 1.6 per 10 000. For the individual practitioner, this will be 0.4 patients per year. The GP probably does encounter one adhesion-related bowel obstruction every two to three years. Previous questionnaire survey among medical specialists into the consequences of intestinal obstructions/adhesions A survey solicited surgeons and gynaecologists responses in Germany, Great Britain and the Netherlands, using questionnaires specifically tailored to each of the three countries. The surveys revealed major variations in medical practices in the countries concerned. The common denominator was that the formation of adhesions after surgery is responsible for a considerable burden of disease. The more negative the respondents’ view of the consequences, the greater the efforts they invested in the prevention of adhesions (4). There was a need for clarity concerning the treatment and prophylaxis of adhesions (5). Dutch gynaecologists were least likely (5%) to discuss the risks of adhesion with their patients before the operation (informed consent) (6). German gynaecologists asked for informed consent in 81% of cases before the operations (7). There was insufficient knowledge among Dutch gynaecologists about adhesions and their consequences (6). All respondents shared the opinion that adhesions might be prevented more with laparoscopy instead of laparotomy. Anti-adhesive agents were infrequently applied.
Problem definition for bowel obstruction and adhesions in general practice Whereas many specialists take great interest in patients with adhesions, there is limited interest in them in the general practice literature. A broad exploratory search in PubMed with the key words, general practice, bowel obstruction, adhesions, surgery-induced, only yielded a few sentences in some primary care guidelines and strikingly some medico-legal papers. Little is known about the way GPs handle cases of bowel obstruction and their
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management for patients with symptoms possibly or directly related to postoperative adhesions. Do they refer patients with complaints due to adhesions? To what extent are GPs familiar with patient education and guidance? Do they know about secondary prevention, such as the existence and usage of anti-adhesive agents? Therefore, a survey was conducted amongst Dutch GPs to investigate their knowledge about bowel obstruction, abdominal adhesions and related complaints, their treatment strategy and referral pattern.
METHODS Study design and setting The objective of the current study is to disclose the experience of GPs about bowel obstruction and abdominal adhesions, their treatment strategy, their level of knowledge of adhesion-related complaints and the referral pattern. Hence the type of survey, there was no need to obtain ethical approval. Developing a questionnaire on bowel obstruction and abdominal adhesions in general practice In the period of preparing the form and content of the questionnaire six experienced GPs were asked (RL) about their attitude towards abdominal complaints due to (postoperative) adhesions and (recurrent) bowel obstruction. The results were re-modelled into a questionnaire by two experienced doctors (MS and RL). The questionnaire consisted of 29 questions over five themes, divided into blocks: experience with bowel obstruction, experience with adhesions, treatment strategy for recurrent complaints, knowledge of and opinions about presumed or existing abdominal adhesions. The items were to be answered on a Likert scale (range: 0–5; completely disagree, disagree, neutral, agree, completely agree). Some questions about differential diagnosis and treatment options allowed a textual answer. The last open question invited written personal opinions, if any (Web only supplement). Two educationalists performed a linguistic and semantic check of the questions (DD and LS). The relevance of the topics was assessed by the Dutch Adhesion Group; a committee of surgeons and gynaecologists with special attention for adhesions. Distribution of the questionnaire The required number of respondents for a representative sample from all Dutch GPs (n ⫽ 10 600; 7901 fulltime equivalents) was calculated to be 800 (8). GPs were contacted by postal mail. The Netherlands Institute for Health Services Research (NIVEL) provided us with upto-date postal addresses of all GPs (9). Questionnaires
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were sent in October 2012 and were followed by two reminders in January and March 2013.
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RESULTS Of the sample of 800 GPs, 361 (45%) returned the questionnaire. One hundred and ninety (24%) respondents had filled out the questionnaire completely. Ninety-nine (12%) questionnaires were sent back blank. The reasons this group gave was absence of experience with bowel obstruction. Fifty-seven (6%) had no time to participate (n ⫽ 57) and 15 respondents (2%) did not specify their reason not to participate. The readiness to fill out the questionnaire was lowest in doctors with less than five years or more than 35 years of clinical experience (Figure 1). Respondents who completed the questionnaire were compared in terms of practice characteristics with the population of Dutch GPs as registered in November 2011 (10). Respondents were more likely to run a singlehanded practice in rural areas, their practice size tended to be larger than average (Table 1). Experience with bowel obstruction Amongst the 190 questionnaires filled out completely, 27% considered bowel obstruction to be an important clinical problem. Seventy-five per cent saw up to three new cases of bowel obstruction per year in their practice (2.69, SD: 2.23, n ⫽ 171). Eighty-three per cent stated that dynamic inhibition (ileus) is the cause of bowel obstruction only in a minority of patients. Bowel malignancy was most frequently mentioned as the cause of mechanical bowel obstruction (78%), followed by faecal impaction (72%), intra-abdominal adhesions (64%), diverticulitis (60%) and Crohn’s disease (30%).
Experience with intra-abdominal adhesions Sixty-seven per cent of the respondents considered intraabdominal adhesions to be a relevant clinical problem. Thirty-four per cent reported an association between postoperative adhesions and an increase in bowel obstructions. Respondents in 76% linked these adhesions to operations on the bowel and even more (86%) linked the complaints of inhibited intestinal transit to adhesions. Thirty per cent of the respondents indicated that they encounter patients who link their current abdominal complaints to their surgical past. When asked, 86% indicated that they consider a history of abdominal surgery regularly or often as a possible cause of pain. The risk of postoperative adhesions was perceived to depend on the type of abdominal surgery. Apart from adhesions caused by surgical intervention, the GPs indicated 21 other reasons for adhesion induction (e.g. inflammatory bowel disease, peritonitis, and endometriosis). Seventy-one per cent of the respondents indicated that they distinguished complaints caused by adhesions from complaints caused by irritable bowel syndrome (IBS). However, 78% reported that they found this differentiation difficult when confronted with a specific clinical situation. Management of obstruction-related complaints Forty-six per cent of the respondents educated their patients about obstruction-related complaints, and 64% give regular nutritional advice to overcome obstructionrelated problems. They mentioned extra fibres (45% of 188 recommendations), extra fluid intake (34%) and laxative diet (11%). Ten per cent of the 190 respondents did not prescribe any drugs while 25% prescribed paracetamol, 28% opted for antispasmodic drugs and 80%
40 35 30 25 20 15 10 5 0
0-4
5-9
10-14
15-19
20-24
25-29
30-34
Clincal experience - clustered per 5 years
Figure 1. Reported clinical experience of the 190 respondents who filled out the questionnaire about bowel obstruction and abdominal adhesions. The X-axis contains the 5 years clusters of experience. The Y-axis informs about absolute numbers of responding GPs in each cluster.
Postoperative adhesions and bowel obstruction Table 1. Characteristics of 190 GPs who completed the questionnaire, compared with the national database of actively practicing GPs in the Netherlands (NIVEL)a. Respondents of this survey Male respondent Practice structure Single-handed Partnership Practice location Urban area Mixed urban/rural Rural area Full-time practice Mean practice size
NIVEL database of GPs
69%
65%
32% 66.5%
18% 80%
P-value 0.500b ⬍ 0.001b
0.019c 41.5% 41.5% 17% 43.9% 2510 patients
47.6% 41.4% 11 %b 44.7% 2371 patients
0.410b 0.057d
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aNIVEL: (Nederlands Instituut voor Eerstelijn) The Netherlands Institute
for Primary Care. bOne sample binominal test. cOne sample t-test. dOne sample Chi-square test.
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Twenty-one per cent had the impression that surgeons informed patients prior to the operation about postoperative adhesions. Nineteen per cent thought that gynaecologists would do so. Forty-two per cent of the GPs reported having sufficient knowledge about strategies for primary and secondary adhesion prevention. Only 12% knew about the existence and use of anti-adhesive agents in abdominal surgery. In the free text part of the questionnaire, 47 GPs mentioned knowledge gaps. Some indicated that they rarely counselled patients with abdominal adhesions (n ⫽ 13), the experience was lacking (n ⫽ 8). Some partakers encouraged the provision of more training (n ⫽ 8). A GP added: ‘It is an underexposed subject in general medicine, and more practical updates are desirable.’
DISCUSSION provided laxatives (Figure 2). Only 40% of the GPs were willing to arrange a referral to specialist care when they considered adhesions to be the cause of the abdominal complaints. Knowledge about bowel obstruction and adhesions Eleven per cent of the respondents considered adhesiolysis to be the best option in chronic abdominal complaints due to adhesions. Seventy per cent expected a decrease in the incidence of adhesion formation with increasing use of laparoscopic surgery. In line with this expectation, 51% preferred laparoscopic procedures when adhesiolysis was indicated. One in four respondents felt competent to educate patients about adhesions prior to a surgical procedure, and reported having sufficient knowledge to advise and monitor these patients.
Main findings The respondents (n ⫽ 190) did not consider bowel obstruction as a difficult clinical challenge. They estimated an incidence of two to three obstructions per GP per year. The respondents identified the causes of obstruction. They reported that adhesions were included in their differential diagnoses. Their opinion was that many patients were not aware of this relation. Distinguishing bowel obstructions from IBS did not present major problems. The pharmacological treatment mostly was the prescription of laxatives (Figure 2). Forty-six per cent explained the recurrence of the complaints. They gave nutritional advice in 64%. They were not inclined to refer patients to a specialist for adhesiolysis. GPs suppose that the introduction of laparoscopies will decrease adhesions. The competence to explain and advise in adhesions exists in about 25% of the respondents.
180 160 140 120 100 80 60 40 20 0
Figure 2. Prescriptions totals in specified categories for obstructive complaints, mentioned by 190 respondents. GPs could note more than one drug.
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Intestinal operations induce the highest percentage of adhesions. In case of abdominal complaints when adhesions are presumed, 40% of the GPs will consider a referral to a specialist. Finally, the additional comments (n ⫽ 48) include 23 requests for additional evidence, as well as CME.
consequences of missing the diagnosis. Knowledge gaps in this area can lead to patients lodging complaints with disciplinary councils when they experience their problems are given insufficient attention and care by the doctor (13,14). Limitations of the study
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Transit problems after adhesions and IBS Although clearly specified guidelines for IBS exist, there is no certainty about the use of their treatment strategies (10). Obviously, GPs apply any IBS strategy for transit problems in this study. Conversely, it is difficult to differentiate correctly between adhesions and IBS. They consider the prescription of liquid nutrition combined with medication to promote defecation as rational. Obviously, this is the consequence of the considerable level of experience that GPs have with IBS with predominant transit problems. Surprisingly, there is only a little evidence in the literature that poorly digested food components can elicit a mechanical bowel obstruction (11). The prescription of laxatives in bowel obstruction is neither addressed in primary care literature, nor in the Bologna guidelines. Bowel obstruction caused distension through metabolic production of gases and increased excretion of intra-luminal fluid with objective consequences for the peristalsis and pain-perception. It is to be doubted whether drugs affecting the peristalsis (anti-spasmodics) or drugs increasing the gaseous content (lactulose) have any effect. Medication that decreases motility is contraindicated. In this enquiry, indeed, opioids are hardly prescribed. Guidance and referral The respondents confirmed that informed consent was rarely asked for at the hospital, even though this is required. The respondents had high expectations towards laparoscopy as do specialists; this procedure might prevent the formation of adhesions. This primary prevention, however, needs to be addressed. Although, laparoscopy causes fewer adhesive bowel obstructions than open abdominal surgery does, it will not prevent them completely. The average percentage is 1.4% for laparoscopy against 2.4% in open surgery (3). The respondents were reticent about referrals for complaints due to suspected adhesions. This reticence does presume that repeated abdominal operations increase the risk of further adhesions and subsequent complications, and hence referral is of no use (12). Respondents who reported insufficient knowledge asked explicitly for additional training within this topic. The importance of such continuing education courses is also obvious for other reasons. In our literature search, to unveil the importance of bowel obstruction and adhesions, we only found some hits, which focused upon the
The preference for contacting the GPs by postal mail was determined by the availability of reliable postal addresses. These are continually updated by the Dutch NIVEL (9), whereas local databases of email addresses are not. We also opted for a postal survey because we wanted to include as many experienced GPs as possible (15) to obtain a highest image of experiences. Practically, we know that the number of cases a GP has encountered, with adhesions leading towards obstruction, depends on the number of years of practicing. This might explain the number of questionnaires that were returned blank (n ⫽ 171). It is clear that participation in surveys is negatively influenced by the infrequency of conditions; in our view, bowel obstruction and adhesions are two of those (16). The conciseness of the questions (⬍ 1000 words) and the limited time investment required (⬍ 10 min) failed to raise the response rate. The introducing letter offered a clear explanation of the objective of the survey, but even this yielded only a limited response (18). The tacit majority of the invited GPs does not make the evidence of the inquiry stronger. We did dispatch the questionnaire in the months that the Dutch GPs were in conflict with the Ministry of Health about financial issues. They officially announced to contribute a minimum of attendance towards external requests. This may have decreased the response rate as well. The GPs who filled out the questionnaire show affinity with the subject, whereas 99 GPs (12%) do not. This commitment does induce bias in the sense of confounding because experience does affect the tendency to respond. Our primary goal is the disclosure of the involvement of GPs with bowel obstruction and postoperative complications. In this view, it is workable to take this bias for granted. This study is the first inquiry about this matter in the general practice literature. Strength of the study Twenty-nine questions about bowel obstruction and adhesions were filled out completely by 190 GPs. The answers showed a strong interest in the subject. The presumed average incidence of obstruction they mentioned is analogous with the national CBS database. The last open question seduced 48 respondents (25%) to express their knowledge gaps and the plea for further information on the topics addressed in the inquiry. We consider this openness as a further strength of the
Postoperative adhesions and bowel obstruction informal validity of the questionnaire. A propitious effect of the study subject in primary care is the simultaneity with the increased attention in surgical care. The increased interest in adhesions among specialists is an opportunity to revive knowledge about these subjects at GP level.
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surmised. Knowledge about how to educate patients is requested for improvement. Additional information about the scarcity of clinical experience does appeal for CMEs.
ACKNOWLEDGEMENTS
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Implications for further research Adhesions occur in 94% of patients after surgery, although most of them do not experience any complaints. The literature shows that the prevalence of iatrogenic bowel obstruction arising within 10 years after abdominal surgery is 22 or more per 10 000 in the general population (18,19). At the level of the individual GP, we estimate the number of iatrogenic bowel obstruction one in two-tothree years. We believe that many patients seldom experience intestinal transit problems, and if they do so, they probably apply their strategy. In some patients, obstruction develops, and admittance to hospital with blocked transit of intestinal content will occur. Literature shows that 57% of these adhesion-induced obstructions undergo surgery, while 43% are treated conservatively (2). Most patients will be found in the ‘grey’ area of (sometimes recurrent) transit problems, who somehow cope with their complaints. It is likely that partial obstructions precede complete obstructions in the future, with the necessity to be operated upon eventually (20). It is to be understood that an unknown number of patients in primary care is suffering from frequent transit problems. This assumption should primarily be examined by means of qualitative research in recurrently operated patients. It would be clarifying to find out about the experiences of patients in the abovementioned grey area with partial obstructions that resolve ‘spontaneously.’ Which role does play the patient ’s nutritional intake in this respect? What is the contribution of medication? Have these patients developed their personal coping strategy? Do they experience problems addressing their experience to the GP? A better understanding of patients and GPs about factors that slow down or block the intestinal transit might perhaps reduce the acute episodes of sub-obstructions and related clinical consequences.
Conclusion GPs indicate that they do not find it difficult to identify mechanical bowel obstruction, which they encounter a few times a year. The impact of adhesions after abdominal operations is reckoned with, but complaints are difficult to interpret, as GPs generally are not familiar with the consequences. They use the identical treatment strategy for transit problems as for IBS and they hardly refer to specialists when adhesions are
This study is supported financially by the Family Medicine Specialty Training, the Department of Family Medicine, the Department of General Surgery of Maastricht University and out-of-hours GP service Meditta Huisartsenzorg Sittard. The authors should like to acknowledge Professor L. Schuwirth (Flinders University Adelaide, Australia) and Professor D. Dolmans (Maastricht University, Department of Medical Education) for their guidance in constructing the questionnaire. Furthermore, the Dutch Adhesion Group contributed with valuable suggestions and support. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
REFERENCES 1. Catena F, Di Saverio S, Kelly MD, Biffl WL, Ansaloni L, Mandala V, et al. Bologna Guidelines for diagnosis and management of adhesive small bowel obstruction (ASBO): 2010 evidence-based guidelines of the world society of emergency surgery. World J Emerg Surg. 2011;6:5. 2. Menzies D, Ellis H. Intestinal obstruction from adhesions— how big is the problem? Ann R Coll Surg Engl. 1990;72:60–3. 3. ten Broek RP, Issa Y, van Santbrink EJ, Bouvy ND, Kruitwagen RF, Jeekel J, et al. Burden of adhesions in abdominal and pelvic surgery: Systematic review and met-analysis. Br Med J. 2013; 347:f5588. 4. Schreinemacher MH, ten Broek RP, Bakkum EA, van Goor H, Bouvy ND. Adhesion awareness: A national survey of surgeons. World J Surg. 2010;34:2805–12. 5. Trew G, Cooke I, Lower AM, McVeigh M. Postoperative abdominal adhesions—awareness of UK gynaecologists—a survey of members of the Royal College of Obstetricians and Gynaecologists. Gynecol Surg. 2009;6:25–37. 6. Meuleman T, Schreinemacher MH, van Goor H, Bakkum EA, Dorr PJ. Adhesion awareness: A nationwide survey of gynaecologists. Eur J Obstet Gynecol Reprod Biol. 2013;169:353–9. 7. Hackethal A, Sick C, Brueggmann D, Tchartchian G, Wallwiener M, Muenstedt K, et al. Awareness and perception of intra-abdominal adhesions and related consequences: Survey of gynaecologists in German hospitals. Eur J Obstet Gynecol Reprod Biol. 2010; 150:180–9. 8. Bartlett JE, Kotrlik JW, Higgins CC. Organizational research: Determining appropriate sample size in survey research. Inform Tech Learn Perform J. 2001;19:43–50. 9. Hingstman L, Kenens R. Data from the registration of general practitioners 2011. Cijfers uit de registratie van huisartsen 2011. Utrecht: Nivel; 2011. 10. Bijkerk CJ, de Wit NJ, Stalman WA, Knottnerus JA, Hoes AW, Muris JW. Irritable bowel syndrome in primary care: The patients’
182
11.
12. 13. 14.
Downloaded by [University of Otago] at 23:41 05 October 2015
15.
R. M. F. M. Leclercq et al. and doctors’ views on symptoms, etiology and management. Can J Gastroenterol. 2003;17:363–8;quiz405–6. Kux M, Fuchsjager N, Baraka A. Food-induced ileus associated with intraperitoneal adhesions. Nahrungsmittelileus bei intraperitonealen Adhasionen. Dtsch Med Wochenschr. 1986; 111:1277–80. van Goor H. Consequences and complications of peritoneal adhesions. Colorectal Dis. 2007;9(Suppl.2):25–34. Bird S. Failure to diagnose: Bowel obstruction. Aust Fam Physician 2008;37:949–50. Ellis H. Medicolegal consequences of postoperative intraabdominal adhesions. J R Soc Med. 2001;94:331–2. Perneger TV, Etter JF, Rougemont A. Randomized trial of use of a monetary incentive and a reminder card to increase the response rate to a mailed health survey. Am J Epidemiol. 1993; 138:714–22.
16. Greenlaw C, Brown-Welty S. A comparison of web-based and paper-based survey methods: Testing assumptions of survey mode and response cost. Eval Rev. 2009;33:464–80. 17. Hummers-Pradier E, Scheidt-Nave C, Martin H, Heinemann S, Kochen MM, Himmel W. Simply no time? Barriers to GPs’ participation in primary health care research. Fam Pract. 2008; 25:105–12. 18. Ellis H, Moran BJ, Thompson JN, Parker MC, Wilson MS, Menzies D, et al. Adhesion-related hospital readmissions after abdominal and pelvic surgery: A retrospective cohort study. Lancet 1999; 353:1476–80. 19. Foster NM, McGory ML, Zingmond DS, Ko CY. Small bowel obstruction: A population-based appraisal. J Am Coll Surg. 2006;203:170–6. 20. Carmichael JC, Mills S. Reoperation for small bowel obstruction— how critical is the timing? Clin Colon Rectal Surg. 2006;19:181–7.
ISSN: 1381-4788 (Print) 1751-1402 (Online) Journal homepage: http://www.tandfonline.com/loi/igen20
Postoperative abdominal adhesions and bowel obstruction. A survey among Dutch general practitioners Raymond MFM Leclercq, Kevin WY Van Barneveld, Marc HF Schreinemacher, Roxanne Assies, Mascha Twellaar, Nicole D Bouvy & Jean WM Muris To cite this article: Raymond MFM Leclercq, Kevin WY Van Barneveld, Marc HF Schreinemacher, Roxanne Assies, Mascha Twellaar, Nicole D Bouvy & Jean WM Muris (2015) Postoperative abdominal adhesions and bowel obstruction. A survey among Dutch general practitioners, European Journal of General Practice, 21:3, 176-182, DOI: 10.3109/13814788.2015.1055466 To link to this article: http://dx.doi.org/10.3109/13814788.2015.1055466
Published online: 10 Jul 2015.
Submit your article to this journal
Article views: 60
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=igen20 Download by: [University of Otago]
Date: 05 October 2015, At: 23:41
European Journal of General Practice, 2015; 21: 176–182
Original Article
Postoperative abdominal adhesions and bowel obstruction. A survey among Dutch general practitioners
Downloaded by [University of Otago] at 23:41 05 October 2015
Raymond MFM Leclercq1, Kevin WY Van Barneveld 2, Marc HF Schreinemacher2, Roxanne Assies2, Mascha Twellaar 1, Nicole D Bouvy2 & Jean WM Muris1 1Department of Family Medicine, CAPHRI School for Public Health and Primary Care, Maastricht University, Maastricht, the Netherlands, 2Department of General Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, the Netherlands
KEY MESSAGE: • • •
GPs believe that bowel malignancy, faecal impaction, adhesions and diverticulitis are the most frequent causes of bowel obstruction. Most GPs differentiate adhesion-related complaints from IBS, in reverse specific patients are difficult to identify. Half of the GPs educate patients about obstructive bowel complaints, more than half advise laxatives, extra fluid and fibres.
ABSTRACT Background: There is increasing interest among specialists in the complications after abdominal surgery due to adhesions. Objective: Exploration of experiences, attitudes and expectations of general practitioners concerning bowel obstruction and postoperative abdominal adhesions. Methods: In October 2012 a postal questionnaire was sent to a random sample of 800 Dutch GPs. Results: The response rate was 45%, 24% (n ⫽ 190) filled out the questionnaire completely, 12% (n ⫽ 99) had no experience with the subject and 7% (n ⫽ 57) had no time to respond. A history of abdominal surgery does play a part in more than 80% of GP’s differential diagnosis of abdominal complaints. Seventy-five per cent consider some types of surgery to induce more adhesions. Eighty-five per cent ponder the differentiation between adhesion related complaints and IBS as clear, however difficult (78%) in specific patients. Intestinal transit problems likely due to adhesions are treated with extra fluid (n ⫽ 64), more fibres (n ⫽ 85) and laxatives (n ⫽ 153). Referral to a specialist for adhesiolysis is rarely considered (11%). Forty per cent of the GPs would refer a patient with abdominal pain and suspected adhesions. Seventy-six per cent denote knowledge gaps and low experience in the treatment of intestinal transit problems. Some (n ⫽ 23) indicate the need for information about adhesions and obstruction through CME papers. Conclusion: Respondents are well equipped to deal with abdominal complaints and intestinal transit problems due to postoperative adhesions. Some indicate the need for information about adhesions and prevention of obstruction through CME papers.
Keywords: Intestinal obstruction, adhesions, surgery-induced, postal survey, general practice
INTRODUCTION In general practice, essential dimensions are personal, continuous and integrated care. These dimensions can be compromised with the existence of rare conditions, such as bowel obstruction and postoperative adhesions. The interest in postoperative adhesions lies especially with
surgeons and gynaecologists and is sometimes found among general practice researchers, making this iatrogenic condition a multidisciplinary issue. One result of this interest is the establishment of the Bologna guidelines for surgeons (1). These guidelines debate the prevention and treatment of postoperative adhesions and their consequences.
Correspondence: Raymond M. F. M. Leclercq, Dept. Family Medicine, PO Box 616, 6200 MD Maastricht, The Netherlands. Fax: ⫹ 31 43 3619344. E-mail: rmfm.leclercq@ maastrichtuniversity.nl (Received 15 October 2013; revised 24 April 2015; accepted 9 May 2015) ISSN 1381-4788 print/ISSN 1751-1402 online © 2015 Informa Healthcare DOI: 10.3109/13814788.2015.1055466
Postoperative adhesions and bowel obstruction
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Operations induce adhesions Per year at least 70 abdominal operations per 10 000 citizens in the Netherlands are being performed (http:// statline.cbs.nl). It is estimated that adhesions arise after 94% of abdominal operations (2). Bowel obstruction due to postoperative adhesions does occur in 2.4% of patients per year after surgery (3). The overall incidence rates for bowel obstructions and ileus in the Netherlands was eleven per 10 000 citizens in 2012 (http://statline.cbs. nl). Implemented into the daily practice, the GP will be confronted with at least three episodes of bowel obstruction per year. The proportion of adhesion-induced bowel obstruction is 2.4% of all abdominal operations and is equivalent with an incidence of 1.6 per 10 000. For the individual practitioner, this will be 0.4 patients per year. The GP probably does encounter one adhesion-related bowel obstruction every two to three years. Previous questionnaire survey among medical specialists into the consequences of intestinal obstructions/adhesions A survey solicited surgeons and gynaecologists responses in Germany, Great Britain and the Netherlands, using questionnaires specifically tailored to each of the three countries. The surveys revealed major variations in medical practices in the countries concerned. The common denominator was that the formation of adhesions after surgery is responsible for a considerable burden of disease. The more negative the respondents’ view of the consequences, the greater the efforts they invested in the prevention of adhesions (4). There was a need for clarity concerning the treatment and prophylaxis of adhesions (5). Dutch gynaecologists were least likely (5%) to discuss the risks of adhesion with their patients before the operation (informed consent) (6). German gynaecologists asked for informed consent in 81% of cases before the operations (7). There was insufficient knowledge among Dutch gynaecologists about adhesions and their consequences (6). All respondents shared the opinion that adhesions might be prevented more with laparoscopy instead of laparotomy. Anti-adhesive agents were infrequently applied.
Problem definition for bowel obstruction and adhesions in general practice Whereas many specialists take great interest in patients with adhesions, there is limited interest in them in the general practice literature. A broad exploratory search in PubMed with the key words, general practice, bowel obstruction, adhesions, surgery-induced, only yielded a few sentences in some primary care guidelines and strikingly some medico-legal papers. Little is known about the way GPs handle cases of bowel obstruction and their
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management for patients with symptoms possibly or directly related to postoperative adhesions. Do they refer patients with complaints due to adhesions? To what extent are GPs familiar with patient education and guidance? Do they know about secondary prevention, such as the existence and usage of anti-adhesive agents? Therefore, a survey was conducted amongst Dutch GPs to investigate their knowledge about bowel obstruction, abdominal adhesions and related complaints, their treatment strategy and referral pattern.
METHODS Study design and setting The objective of the current study is to disclose the experience of GPs about bowel obstruction and abdominal adhesions, their treatment strategy, their level of knowledge of adhesion-related complaints and the referral pattern. Hence the type of survey, there was no need to obtain ethical approval. Developing a questionnaire on bowel obstruction and abdominal adhesions in general practice In the period of preparing the form and content of the questionnaire six experienced GPs were asked (RL) about their attitude towards abdominal complaints due to (postoperative) adhesions and (recurrent) bowel obstruction. The results were re-modelled into a questionnaire by two experienced doctors (MS and RL). The questionnaire consisted of 29 questions over five themes, divided into blocks: experience with bowel obstruction, experience with adhesions, treatment strategy for recurrent complaints, knowledge of and opinions about presumed or existing abdominal adhesions. The items were to be answered on a Likert scale (range: 0–5; completely disagree, disagree, neutral, agree, completely agree). Some questions about differential diagnosis and treatment options allowed a textual answer. The last open question invited written personal opinions, if any (Web only supplement). Two educationalists performed a linguistic and semantic check of the questions (DD and LS). The relevance of the topics was assessed by the Dutch Adhesion Group; a committee of surgeons and gynaecologists with special attention for adhesions. Distribution of the questionnaire The required number of respondents for a representative sample from all Dutch GPs (n ⫽ 10 600; 7901 fulltime equivalents) was calculated to be 800 (8). GPs were contacted by postal mail. The Netherlands Institute for Health Services Research (NIVEL) provided us with upto-date postal addresses of all GPs (9). Questionnaires
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were sent in October 2012 and were followed by two reminders in January and March 2013.
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RESULTS Of the sample of 800 GPs, 361 (45%) returned the questionnaire. One hundred and ninety (24%) respondents had filled out the questionnaire completely. Ninety-nine (12%) questionnaires were sent back blank. The reasons this group gave was absence of experience with bowel obstruction. Fifty-seven (6%) had no time to participate (n ⫽ 57) and 15 respondents (2%) did not specify their reason not to participate. The readiness to fill out the questionnaire was lowest in doctors with less than five years or more than 35 years of clinical experience (Figure 1). Respondents who completed the questionnaire were compared in terms of practice characteristics with the population of Dutch GPs as registered in November 2011 (10). Respondents were more likely to run a singlehanded practice in rural areas, their practice size tended to be larger than average (Table 1). Experience with bowel obstruction Amongst the 190 questionnaires filled out completely, 27% considered bowel obstruction to be an important clinical problem. Seventy-five per cent saw up to three new cases of bowel obstruction per year in their practice (2.69, SD: 2.23, n ⫽ 171). Eighty-three per cent stated that dynamic inhibition (ileus) is the cause of bowel obstruction only in a minority of patients. Bowel malignancy was most frequently mentioned as the cause of mechanical bowel obstruction (78%), followed by faecal impaction (72%), intra-abdominal adhesions (64%), diverticulitis (60%) and Crohn’s disease (30%).
Experience with intra-abdominal adhesions Sixty-seven per cent of the respondents considered intraabdominal adhesions to be a relevant clinical problem. Thirty-four per cent reported an association between postoperative adhesions and an increase in bowel obstructions. Respondents in 76% linked these adhesions to operations on the bowel and even more (86%) linked the complaints of inhibited intestinal transit to adhesions. Thirty per cent of the respondents indicated that they encounter patients who link their current abdominal complaints to their surgical past. When asked, 86% indicated that they consider a history of abdominal surgery regularly or often as a possible cause of pain. The risk of postoperative adhesions was perceived to depend on the type of abdominal surgery. Apart from adhesions caused by surgical intervention, the GPs indicated 21 other reasons for adhesion induction (e.g. inflammatory bowel disease, peritonitis, and endometriosis). Seventy-one per cent of the respondents indicated that they distinguished complaints caused by adhesions from complaints caused by irritable bowel syndrome (IBS). However, 78% reported that they found this differentiation difficult when confronted with a specific clinical situation. Management of obstruction-related complaints Forty-six per cent of the respondents educated their patients about obstruction-related complaints, and 64% give regular nutritional advice to overcome obstructionrelated problems. They mentioned extra fibres (45% of 188 recommendations), extra fluid intake (34%) and laxative diet (11%). Ten per cent of the 190 respondents did not prescribe any drugs while 25% prescribed paracetamol, 28% opted for antispasmodic drugs and 80%
40 35 30 25 20 15 10 5 0
0-4
5-9
10-14
15-19
20-24
25-29
30-34
Clincal experience - clustered per 5 years
Figure 1. Reported clinical experience of the 190 respondents who filled out the questionnaire about bowel obstruction and abdominal adhesions. The X-axis contains the 5 years clusters of experience. The Y-axis informs about absolute numbers of responding GPs in each cluster.
Postoperative adhesions and bowel obstruction Table 1. Characteristics of 190 GPs who completed the questionnaire, compared with the national database of actively practicing GPs in the Netherlands (NIVEL)a. Respondents of this survey Male respondent Practice structure Single-handed Partnership Practice location Urban area Mixed urban/rural Rural area Full-time practice Mean practice size
NIVEL database of GPs
69%
65%
32% 66.5%
18% 80%
P-value 0.500b ⬍ 0.001b
0.019c 41.5% 41.5% 17% 43.9% 2510 patients
47.6% 41.4% 11 %b 44.7% 2371 patients
0.410b 0.057d
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aNIVEL: (Nederlands Instituut voor Eerstelijn) The Netherlands Institute
for Primary Care. bOne sample binominal test. cOne sample t-test. dOne sample Chi-square test.
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Twenty-one per cent had the impression that surgeons informed patients prior to the operation about postoperative adhesions. Nineteen per cent thought that gynaecologists would do so. Forty-two per cent of the GPs reported having sufficient knowledge about strategies for primary and secondary adhesion prevention. Only 12% knew about the existence and use of anti-adhesive agents in abdominal surgery. In the free text part of the questionnaire, 47 GPs mentioned knowledge gaps. Some indicated that they rarely counselled patients with abdominal adhesions (n ⫽ 13), the experience was lacking (n ⫽ 8). Some partakers encouraged the provision of more training (n ⫽ 8). A GP added: ‘It is an underexposed subject in general medicine, and more practical updates are desirable.’
DISCUSSION provided laxatives (Figure 2). Only 40% of the GPs were willing to arrange a referral to specialist care when they considered adhesions to be the cause of the abdominal complaints. Knowledge about bowel obstruction and adhesions Eleven per cent of the respondents considered adhesiolysis to be the best option in chronic abdominal complaints due to adhesions. Seventy per cent expected a decrease in the incidence of adhesion formation with increasing use of laparoscopic surgery. In line with this expectation, 51% preferred laparoscopic procedures when adhesiolysis was indicated. One in four respondents felt competent to educate patients about adhesions prior to a surgical procedure, and reported having sufficient knowledge to advise and monitor these patients.
Main findings The respondents (n ⫽ 190) did not consider bowel obstruction as a difficult clinical challenge. They estimated an incidence of two to three obstructions per GP per year. The respondents identified the causes of obstruction. They reported that adhesions were included in their differential diagnoses. Their opinion was that many patients were not aware of this relation. Distinguishing bowel obstructions from IBS did not present major problems. The pharmacological treatment mostly was the prescription of laxatives (Figure 2). Forty-six per cent explained the recurrence of the complaints. They gave nutritional advice in 64%. They were not inclined to refer patients to a specialist for adhesiolysis. GPs suppose that the introduction of laparoscopies will decrease adhesions. The competence to explain and advise in adhesions exists in about 25% of the respondents.
180 160 140 120 100 80 60 40 20 0
Figure 2. Prescriptions totals in specified categories for obstructive complaints, mentioned by 190 respondents. GPs could note more than one drug.
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Intestinal operations induce the highest percentage of adhesions. In case of abdominal complaints when adhesions are presumed, 40% of the GPs will consider a referral to a specialist. Finally, the additional comments (n ⫽ 48) include 23 requests for additional evidence, as well as CME.
consequences of missing the diagnosis. Knowledge gaps in this area can lead to patients lodging complaints with disciplinary councils when they experience their problems are given insufficient attention and care by the doctor (13,14). Limitations of the study
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Transit problems after adhesions and IBS Although clearly specified guidelines for IBS exist, there is no certainty about the use of their treatment strategies (10). Obviously, GPs apply any IBS strategy for transit problems in this study. Conversely, it is difficult to differentiate correctly between adhesions and IBS. They consider the prescription of liquid nutrition combined with medication to promote defecation as rational. Obviously, this is the consequence of the considerable level of experience that GPs have with IBS with predominant transit problems. Surprisingly, there is only a little evidence in the literature that poorly digested food components can elicit a mechanical bowel obstruction (11). The prescription of laxatives in bowel obstruction is neither addressed in primary care literature, nor in the Bologna guidelines. Bowel obstruction caused distension through metabolic production of gases and increased excretion of intra-luminal fluid with objective consequences for the peristalsis and pain-perception. It is to be doubted whether drugs affecting the peristalsis (anti-spasmodics) or drugs increasing the gaseous content (lactulose) have any effect. Medication that decreases motility is contraindicated. In this enquiry, indeed, opioids are hardly prescribed. Guidance and referral The respondents confirmed that informed consent was rarely asked for at the hospital, even though this is required. The respondents had high expectations towards laparoscopy as do specialists; this procedure might prevent the formation of adhesions. This primary prevention, however, needs to be addressed. Although, laparoscopy causes fewer adhesive bowel obstructions than open abdominal surgery does, it will not prevent them completely. The average percentage is 1.4% for laparoscopy against 2.4% in open surgery (3). The respondents were reticent about referrals for complaints due to suspected adhesions. This reticence does presume that repeated abdominal operations increase the risk of further adhesions and subsequent complications, and hence referral is of no use (12). Respondents who reported insufficient knowledge asked explicitly for additional training within this topic. The importance of such continuing education courses is also obvious for other reasons. In our literature search, to unveil the importance of bowel obstruction and adhesions, we only found some hits, which focused upon the
The preference for contacting the GPs by postal mail was determined by the availability of reliable postal addresses. These are continually updated by the Dutch NIVEL (9), whereas local databases of email addresses are not. We also opted for a postal survey because we wanted to include as many experienced GPs as possible (15) to obtain a highest image of experiences. Practically, we know that the number of cases a GP has encountered, with adhesions leading towards obstruction, depends on the number of years of practicing. This might explain the number of questionnaires that were returned blank (n ⫽ 171). It is clear that participation in surveys is negatively influenced by the infrequency of conditions; in our view, bowel obstruction and adhesions are two of those (16). The conciseness of the questions (⬍ 1000 words) and the limited time investment required (⬍ 10 min) failed to raise the response rate. The introducing letter offered a clear explanation of the objective of the survey, but even this yielded only a limited response (18). The tacit majority of the invited GPs does not make the evidence of the inquiry stronger. We did dispatch the questionnaire in the months that the Dutch GPs were in conflict with the Ministry of Health about financial issues. They officially announced to contribute a minimum of attendance towards external requests. This may have decreased the response rate as well. The GPs who filled out the questionnaire show affinity with the subject, whereas 99 GPs (12%) do not. This commitment does induce bias in the sense of confounding because experience does affect the tendency to respond. Our primary goal is the disclosure of the involvement of GPs with bowel obstruction and postoperative complications. In this view, it is workable to take this bias for granted. This study is the first inquiry about this matter in the general practice literature. Strength of the study Twenty-nine questions about bowel obstruction and adhesions were filled out completely by 190 GPs. The answers showed a strong interest in the subject. The presumed average incidence of obstruction they mentioned is analogous with the national CBS database. The last open question seduced 48 respondents (25%) to express their knowledge gaps and the plea for further information on the topics addressed in the inquiry. We consider this openness as a further strength of the
Postoperative adhesions and bowel obstruction informal validity of the questionnaire. A propitious effect of the study subject in primary care is the simultaneity with the increased attention in surgical care. The increased interest in adhesions among specialists is an opportunity to revive knowledge about these subjects at GP level.
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surmised. Knowledge about how to educate patients is requested for improvement. Additional information about the scarcity of clinical experience does appeal for CMEs.
ACKNOWLEDGEMENTS
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Implications for further research Adhesions occur in 94% of patients after surgery, although most of them do not experience any complaints. The literature shows that the prevalence of iatrogenic bowel obstruction arising within 10 years after abdominal surgery is 22 or more per 10 000 in the general population (18,19). At the level of the individual GP, we estimate the number of iatrogenic bowel obstruction one in two-tothree years. We believe that many patients seldom experience intestinal transit problems, and if they do so, they probably apply their strategy. In some patients, obstruction develops, and admittance to hospital with blocked transit of intestinal content will occur. Literature shows that 57% of these adhesion-induced obstructions undergo surgery, while 43% are treated conservatively (2). Most patients will be found in the ‘grey’ area of (sometimes recurrent) transit problems, who somehow cope with their complaints. It is likely that partial obstructions precede complete obstructions in the future, with the necessity to be operated upon eventually (20). It is to be understood that an unknown number of patients in primary care is suffering from frequent transit problems. This assumption should primarily be examined by means of qualitative research in recurrently operated patients. It would be clarifying to find out about the experiences of patients in the abovementioned grey area with partial obstructions that resolve ‘spontaneously.’ Which role does play the patient ’s nutritional intake in this respect? What is the contribution of medication? Have these patients developed their personal coping strategy? Do they experience problems addressing their experience to the GP? A better understanding of patients and GPs about factors that slow down or block the intestinal transit might perhaps reduce the acute episodes of sub-obstructions and related clinical consequences.
Conclusion GPs indicate that they do not find it difficult to identify mechanical bowel obstruction, which they encounter a few times a year. The impact of adhesions after abdominal operations is reckoned with, but complaints are difficult to interpret, as GPs generally are not familiar with the consequences. They use the identical treatment strategy for transit problems as for IBS and they hardly refer to specialists when adhesions are
This study is supported financially by the Family Medicine Specialty Training, the Department of Family Medicine, the Department of General Surgery of Maastricht University and out-of-hours GP service Meditta Huisartsenzorg Sittard. The authors should like to acknowledge Professor L. Schuwirth (Flinders University Adelaide, Australia) and Professor D. Dolmans (Maastricht University, Department of Medical Education) for their guidance in constructing the questionnaire. Furthermore, the Dutch Adhesion Group contributed with valuable suggestions and support. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
REFERENCES 1. Catena F, Di Saverio S, Kelly MD, Biffl WL, Ansaloni L, Mandala V, et al. Bologna Guidelines for diagnosis and management of adhesive small bowel obstruction (ASBO): 2010 evidence-based guidelines of the world society of emergency surgery. World J Emerg Surg. 2011;6:5. 2. Menzies D, Ellis H. Intestinal obstruction from adhesions— how big is the problem? Ann R Coll Surg Engl. 1990;72:60–3. 3. ten Broek RP, Issa Y, van Santbrink EJ, Bouvy ND, Kruitwagen RF, Jeekel J, et al. Burden of adhesions in abdominal and pelvic surgery: Systematic review and met-analysis. Br Med J. 2013; 347:f5588. 4. Schreinemacher MH, ten Broek RP, Bakkum EA, van Goor H, Bouvy ND. Adhesion awareness: A national survey of surgeons. World J Surg. 2010;34:2805–12. 5. Trew G, Cooke I, Lower AM, McVeigh M. Postoperative abdominal adhesions—awareness of UK gynaecologists—a survey of members of the Royal College of Obstetricians and Gynaecologists. Gynecol Surg. 2009;6:25–37. 6. Meuleman T, Schreinemacher MH, van Goor H, Bakkum EA, Dorr PJ. Adhesion awareness: A nationwide survey of gynaecologists. Eur J Obstet Gynecol Reprod Biol. 2013;169:353–9. 7. Hackethal A, Sick C, Brueggmann D, Tchartchian G, Wallwiener M, Muenstedt K, et al. Awareness and perception of intra-abdominal adhesions and related consequences: Survey of gynaecologists in German hospitals. Eur J Obstet Gynecol Reprod Biol. 2010; 150:180–9. 8. Bartlett JE, Kotrlik JW, Higgins CC. Organizational research: Determining appropriate sample size in survey research. Inform Tech Learn Perform J. 2001;19:43–50. 9. Hingstman L, Kenens R. Data from the registration of general practitioners 2011. Cijfers uit de registratie van huisartsen 2011. Utrecht: Nivel; 2011. 10. Bijkerk CJ, de Wit NJ, Stalman WA, Knottnerus JA, Hoes AW, Muris JW. Irritable bowel syndrome in primary care: The patients’
182
11.
12. 13. 14.
Downloaded by [University of Otago] at 23:41 05 October 2015
15.
R. M. F. M. Leclercq et al. and doctors’ views on symptoms, etiology and management. Can J Gastroenterol. 2003;17:363–8;quiz405–6. Kux M, Fuchsjager N, Baraka A. Food-induced ileus associated with intraperitoneal adhesions. Nahrungsmittelileus bei intraperitonealen Adhasionen. Dtsch Med Wochenschr. 1986; 111:1277–80. van Goor H. Consequences and complications of peritoneal adhesions. Colorectal Dis. 2007;9(Suppl.2):25–34. Bird S. Failure to diagnose: Bowel obstruction. Aust Fam Physician 2008;37:949–50. Ellis H. Medicolegal consequences of postoperative intraabdominal adhesions. J R Soc Med. 2001;94:331–2. Perneger TV, Etter JF, Rougemont A. Randomized trial of use of a monetary incentive and a reminder card to increase the response rate to a mailed health survey. Am J Epidemiol. 1993; 138:714–22.
16. Greenlaw C, Brown-Welty S. A comparison of web-based and paper-based survey methods: Testing assumptions of survey mode and response cost. Eval Rev. 2009;33:464–80. 17. Hummers-Pradier E, Scheidt-Nave C, Martin H, Heinemann S, Kochen MM, Himmel W. Simply no time? Barriers to GPs’ participation in primary health care research. Fam Pract. 2008; 25:105–12. 18. Ellis H, Moran BJ, Thompson JN, Parker MC, Wilson MS, Menzies D, et al. Adhesion-related hospital readmissions after abdominal and pelvic surgery: A retrospective cohort study. Lancet 1999; 353:1476–80. 19. Foster NM, McGory ML, Zingmond DS, Ko CY. Small bowel obstruction: A population-based appraisal. J Am Coll Surg. 2006;203:170–6. 20. Carmichael JC, Mills S. Reoperation for small bowel obstruction— how critical is the timing? Clin Colon Rectal Surg. 2006;19:181–7.
