G Model
AGG-3131; No. of Pages 7 Archives of Gerontology and Geriatrics xxx (2015) xxx–xxx
Contents lists available at ScienceDirect
Archives of Gerontology and Geriatrics journal homepage: www.elsevier.com/locate/archger
A longitudinal study of constipation and laxative use in a community-dwelling elderly population Barry L. Werth a,*, Kylie A. Williams b, Lisa G. Pont a a b
Sydney Nursing School, University of Sydney, Sydney, NSW, Australia Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Sydney, NSW, Australia
A R T I C L E I N F O
A B S T R A C T
Article history: Received 10 August 2014 Received in revised form 27 January 2015 Accepted 9 February 2015 Available online xxx
Background: Little is known about laxative use, the association of constipation with laxative use, risk factors for constipation and how each of these changes over time in the community-dwelling elderly. Objective: The aim was to explore the prevalence of laxative use and of self-reported constipation, and identify risk factors (including age) associated with constipation, in a cohort of community-dwelling elderly residents. Methods: Data from the Australian Longitudinal Study of Ageing (ALSA) was used to compare differences in constipation and laxative use in the community-dwelling elderly between 1992–1993 and 2003– 2004. Results: Relevant data was available for 239 ALSA participants. The prevalence of self-reported constipation increased from 14% in 1992–1993 to 21% in 2003–2004. There was a corresponding increase in the prevalence of laxative use from 6% to 15% over the same period. At both time points, females reported a higher prevalence of both constipation and laxative use however the female:male prevalence ratios decreased over time indicating higher increases in the prevalence of each among males. Persistent chronic constipation occurred in 9% of the cohort. The association between laxative use and self-reported constipation was poor and laxative use was associated with self-reported constipation in less than a third of cases. Conclusion: The prevalence of both constipation and laxative use increases with age in the elderly, and these increases are greater for males than for females. Discrepancies between self-reported constipation and laxative use may suggest sub-optimal management of constipation in the community-dwelling elderly and further work is needed to fully understand this. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: Longitudinal survey Aged Community Constipation Risk factors Laxatives
1. Background Like most developed countries, the Australian population is aging with the majority of the elderly population residing in the community (Luszcz et al., 2007). Constipation is a relatively common condition which is particularly prevalent in the elderly and usually self-managed with laxatives (Gallagher & O’Mahony, 2009; McCrea, Miaskowski, Stotts, Macera, & Varma, 2009). Over $100 million is spent annually in Australia on laxatives but this is only one cost consequence of constipation. The costs of doctor consultations, hospitalisations and lost productivity due to constipation represent a significant additional economic burden (Dennison et al., 2005; Locke, Pemberton, & Phillips, 2000;
* Corresponding author. Tel.: +61 428 115 866. E-mail address: [email protected] (B.L. Werth).
Sonnenberg & Koch, 1989a, 1989b). In addition to the financial costs associated with constipation, the impact on the quality of life of those who suffer with constipation is a further consequence which cannot be ignored (Belsey, Greenfield, Candy, & Geraint, 2010; Dennison et al., 2005; Johanson & Kralstein, 2007; Talley, 2004; Wald et al., 2007). International studies have reported a wide range in the prevalence of constipation in community-dwelling elderly populations (Campbell, Busby, & Horwath, 1993; Chaplin, Curless, Thomson, & Barton, 2000; Hammond, 1964; Wong, Wee, Pin, Gan, & Ye, 1999). Depending on the definition of constipation used, prevalences between 11% and 55% have been reported. Studies using self-defined constipation where participants are free to define constipation themselves without any constraints usually report higher prevalence rates than those using a specified definition or criteria (Wald et al., 2008). A recent US longitudinal study of the general adult population over a period of 20 years
http://dx.doi.org/10.1016/j.archger.2015.02.004 0167-4943/ß 2015 Elsevier Ireland Ltd. All rights reserved.
Please cite this article in press as: Werth, B.L., et al., A longitudinal study of constipation and laxative use in a community-dwelling elderly population. Arch. Gerontol. Geriatr. (2015), http://dx.doi.org/10.1016/j.archger.2015.02.004
G Model
AGG-3131; No. of Pages 7 2
B.L. Werth et al. / Archives of Gerontology and Geriatrics xxx (2015) xxx–xxx
investigated the prevalence of persistent chronic constipation and found that 3% had persistent chronic constipation (Choung et al., 2012) but no longitudinal studies focussed on elderly populations have been published to date. A number of factors associated with an increased risk of constipation have been reported in the general population and one of these risk factors is age. An increase in the prevalence of constipation with age in those older than 60 years has been well documented internationally (Chaplin et al., 2000; Hammond, 1964; Harari, Gurwitz, Avorn, Bohn, & Minaker, 1996; Lu, Chang, Chen, Luo, & Lee, 2006; Nakaji et al., 2002; Wong et al., 1999) with some studies indicating that the largest increases occur after 70–75 years of age (McCrea et al., 2009; Talley, Jones, Nuyts, & Dubois, 2003). In addition to increasing age, other risk factors for constipation identified include gender, co-morbidity and medications. In most studies, females are more likely to report constipation than males (Campbell et al., 1993; Stewart, Moore, Marks, & Hale, 1992; Talley et al., 1996). Other risk factors which have been reported in elderly populations include low levels of physical activity (Brown, Mishra, Lee, & Bauman, 2000), medical conditions such as stress, stroke, heart conditions (Wong et al., 1999) and hemorrhoids (Chiarelli, Brown, & McElduff, 2000), and medications such as diuretics, calcium channel blockers, antidepressants and hypnotics (Campbell et al., 1993; Chiarelli et al., 2000; Wong et al., 1999). Whilst some international studies have reported the prevalence of constipation and risk factors in community-dwelling elderly populations, less is known about the management of constipation and the use of laxatives. Several international studies have reported the prevalence of laxative use in the community-dwelling elderly ranging from 10% to 25% (Campbell et al., 1993; Chaplin et al., 2000; Marfil, Davies, & Dettmar, 2005; May, Stewart, Hale, & Marks, 1982; Pahor, Guralnik, Chrischilles, & Wallace, 1994; Ruby, Fillenbaum, Kuchibhatla, & Hanlon, 2003; Stoehr, Ganguli, Seaberg, Echement, & Belle, 1997; Stoller, 1988; Whitehead, Drinkwater, Cheskin, Heller, & Schuster, 1989). The reported prevalence may vary according to the definition of laxative used, and whether the laxative was prescribed or non-prescribed. U.S. studies have found laxative use to be higher in females than males (May et al., 1982; Stoehr et al., 1997), laxative usage increases with age (Stoehr et al., 1997) and, with the exception of lactulose, all laxative products were over-the-counter (OTC) medicines with few prescribed by doctors (Ruby et al., 2003). However there have been few Australian studies of constipation and laxative use in the community dwelling elderly, and no published Australian study has investigated the association of laxative use with constipation in any population. In fact, the prevalence of laxative use and its association with constipation in the community-dwelling elderly has not been extensively studied either in Australia or internationally, nor have these issues been examined on a longitudinal basis. 2. Objective The aim of our study was to determine the impact of aging on the prevalence of constipation and laxative use in a cohort of community-dwelling elderly residents. We also aimed to explore changes in various risk factors associated with constipation over time. 3. Methods 3.1. Data source The Australian Longitudinal Study of Ageing (ALSA) is a longitudinal cohort study of aging in the community (Luszcz et al., 2007). The study was conducted in Adelaide, South Australia and commenced in 1992 with 2087 participants aged 65 years or
older. Participants were interviewed and data collected at eight different time points over the next 14 years. The number of participants was reduced over this time due to a variety of reasons including refusal to participate further, ill health, death or being un-contactable. The detailed ALSA methodology has been published previously (Luszcz et al., 2007). At baseline in 1992–1993, face-to-face interviews were conducted at the place of residence of each participant to elicit answers to a wide range of questions regarding their health and welfare. Data on all medical conditions were recorded, including self-reported constipation, as well as data for both prescribed and non-prescribed medications. Interviews and collection of data were repeated in 2003–2004. 3.2. Study population Of the original 2087 participants from 1992–1993, 487 participated in 2003–2004, of whom 412 were living in the community and eligible for inclusion in this analysis. For this study, participants must have had complete constipation and medication use data recorded at both the 1992–1993 and 2003–2004 time points. Participants who did not answer the question regarding constipation (n = 30) or who reported a colostomy (n = 3) were excluded from our analysis, as were participants who did not give consent for medication data to be accessed (n = 140), leaving a total of 239 community-dwelling participants with complete constipation and medication use data in both 1992–1993 and 2003–2004. 3.3. Self-reported constipation At both time points, participants were asked to report on constipation. In 1992–1993, the question was: ‘‘Do you often have trouble with your bowels which makes you constipated?’’ and in 2003–2004 participants were asked a slightly different question: ‘‘Do you have trouble with your bowels which makes you constipated?’’. Also at both time points, the participants were asked about bowel movement frequency: ‘‘How often do you usually have a bowel movement?’’. 3.4. Medication use Two sources of medication use data were used. In 1992–1993, participants were asked to name all medications (both prescribed and purchased over-the-counter) which had been taken in the previous two weeks. Participants were also asked to show the medicine container to the interviewer. In 2003–2004, the same methodology was used for OTC medications but they were also asked whether the OTC medicine was prescribed by a doctor. In addition, medicine reimbursement data was obtained for all prescription medicines which had been subsidized by the Australian government. Both reimbursed and OTC medications included a number of laxative agents. 3.5. Potential risk factors for constipation Potential risk factors for constipation were identified from the literature. These included medical conditions, medications and level of physical activity as well as socio-demographic data. Medications were considered to have the potential to cause constipation if listed as an adverse effect in published reviews of the subject (Branch & Butt, 2009; Toney, Wallace, Sekhon, & Agrawal, 2008). Medical conditions associated with constipation identified in the literature included conditions affecting the heart, lower gastrointestinal system (e.g. hemorrhoids), and musculoskeletal system (Chiarelli et al., 2000; Fosnes, Lydersen, & Farup, 2011; Talley et al., 2003; Wong et al., 1999).
Please cite this article in press as: Werth, B.L., et al., A longitudinal study of constipation and laxative use in a community-dwelling elderly population. Arch. Gerontol. Geriatr. (2015), http://dx.doi.org/10.1016/j.archger.2015.02.004
G Model
AGG-3131; No. of Pages 7 B.L. Werth et al. / Archives of Gerontology and Geriatrics xxx (2015) xxx–xxx
3.6. Analysis Analysis of data was done using IBM SPSS Statistics version 21 (IBM Corporation). For unifactorial analyses of potential risk factors, Pearson’s Chi-squared test, Kruskal–Wallis test and t-test (independent and paired) were used as appropriate. Prevalence at each time point was compared using McNemar’s test. P values of 0.05 or less were considered to be statistically significant. 4. Results 4.1. Study population The majority of the cohort was female (61%) and the mean age of the cohort increased from 73 in 1992–1993 to 84 years in 2003– 2004 (Table 1). Half of the cohort had left school by the age of 14 years and a third had some form of post-school qualification. Although the number of medical conditions reported by each participant did not change greatly over the period, the number of medications taken by each participant increased dramatically over time. Physical activity (functional status) as indicated by the activities of daily living (an assessment of basic self-care tasks) declined over the study period as did levels of self-rated health. 4.2. Constipation A statistically significant increase in the prevalence of constipation was seen between 1992–1993 (13.8%) and 2003– 2004 (20.9%) (Table 1). More females than males reported constipation at both time points however the ratio of females to males declined in 2003–2004 (1.51) compared to 1992–1993 (2.42). The change in the female:male prevalence ratio may be attributed to a doubling in the prevalence of constipation in males over the time. Looking at changes over time for individual participants, 64% (n = 21/33) of participants who reported constipation in 1992– 1993 also reported constipation in 2003–2004 (Table 1). These individuals can be classified as persistent sufferers, representing 9% of the total cohort whereas non-persistent cases, those
3
reporting constipation at one time point only, represented 18% of the total cohort with 73% not reporting constipation at either time point. The frequency of bowel motions did not correlate with selfreported constipation at either time point. Only 12% (n = 4/33) of those reporting constipation in 1992–1993 also reported 3 or fewer bowel motions per week, and in 2003–2004 this figure was 14% (n = 7/50). There was no significant difference in bowel motion frequency between the two time points. Potential risk factors varied between the 1992–1993 and 2003– 2004 time periods (Table 2). Risk factors which were significantly associated with self-reported constipation at both time points included the level of physical activity/functional status, as measured by the activities of daily living (ADL), and the number of medical conditions reported by participants. Also those who reported their health as poor or fair were more likely to report constipation at both time points. In 1992–1993, participants with a post-school qualification were less likely to report constipation and the age at which participants left school was also significant but neither of these factors remained significant in 2003–2004. Certain medical conditions have been reported in the literature as being frequently associated with constipation and these were investigated (Table 2). No significant differences were found in 1992–1993 with regard to constipation and specified co-morbidities with the exception of osteoporosis, however this changed over time. In the 2003–2004 data, heart conditions (including angina), arthritis, hemorrhoids, osteoporosis and muscular complaints were all significant risk factors for constipation. Medication use varied over time. The number of medications used was significantly associated with self-reported constipation in 1992–1993, however despite the number of medications per participant increasing over time, no association between number of medications and self-reported constipation was observed at the second time point (Table 2). Tricyclic antidepressants were the only drugs significantly associated with constipation at both times; other drugs significantly associated with constipation at one time point were diuretics, non-steroidal anti-inflammatory drugs (NSAIDs), opioid analgesics, anti-parkinsonism drugs and clonidine.
Table 1 Participant characteristics, including self-reported constipation (SRC), bowel motions (BM) and laxative use (LU). Characteristic
1992–1993
2003–2004
Mean age (years) Age range (years) Females, n (% of total) Age left school (
AGG-3131; No. of Pages 7 Archives of Gerontology and Geriatrics xxx (2015) xxx–xxx
Contents lists available at ScienceDirect
Archives of Gerontology and Geriatrics journal homepage: www.elsevier.com/locate/archger
A longitudinal study of constipation and laxative use in a community-dwelling elderly population Barry L. Werth a,*, Kylie A. Williams b, Lisa G. Pont a a b
Sydney Nursing School, University of Sydney, Sydney, NSW, Australia Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Sydney, NSW, Australia
A R T I C L E I N F O
A B S T R A C T
Article history: Received 10 August 2014 Received in revised form 27 January 2015 Accepted 9 February 2015 Available online xxx
Background: Little is known about laxative use, the association of constipation with laxative use, risk factors for constipation and how each of these changes over time in the community-dwelling elderly. Objective: The aim was to explore the prevalence of laxative use and of self-reported constipation, and identify risk factors (including age) associated with constipation, in a cohort of community-dwelling elderly residents. Methods: Data from the Australian Longitudinal Study of Ageing (ALSA) was used to compare differences in constipation and laxative use in the community-dwelling elderly between 1992–1993 and 2003– 2004. Results: Relevant data was available for 239 ALSA participants. The prevalence of self-reported constipation increased from 14% in 1992–1993 to 21% in 2003–2004. There was a corresponding increase in the prevalence of laxative use from 6% to 15% over the same period. At both time points, females reported a higher prevalence of both constipation and laxative use however the female:male prevalence ratios decreased over time indicating higher increases in the prevalence of each among males. Persistent chronic constipation occurred in 9% of the cohort. The association between laxative use and self-reported constipation was poor and laxative use was associated with self-reported constipation in less than a third of cases. Conclusion: The prevalence of both constipation and laxative use increases with age in the elderly, and these increases are greater for males than for females. Discrepancies between self-reported constipation and laxative use may suggest sub-optimal management of constipation in the community-dwelling elderly and further work is needed to fully understand this. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: Longitudinal survey Aged Community Constipation Risk factors Laxatives
1. Background Like most developed countries, the Australian population is aging with the majority of the elderly population residing in the community (Luszcz et al., 2007). Constipation is a relatively common condition which is particularly prevalent in the elderly and usually self-managed with laxatives (Gallagher & O’Mahony, 2009; McCrea, Miaskowski, Stotts, Macera, & Varma, 2009). Over $100 million is spent annually in Australia on laxatives but this is only one cost consequence of constipation. The costs of doctor consultations, hospitalisations and lost productivity due to constipation represent a significant additional economic burden (Dennison et al., 2005; Locke, Pemberton, & Phillips, 2000;
* Corresponding author. Tel.: +61 428 115 866. E-mail address: [email protected] (B.L. Werth).
Sonnenberg & Koch, 1989a, 1989b). In addition to the financial costs associated with constipation, the impact on the quality of life of those who suffer with constipation is a further consequence which cannot be ignored (Belsey, Greenfield, Candy, & Geraint, 2010; Dennison et al., 2005; Johanson & Kralstein, 2007; Talley, 2004; Wald et al., 2007). International studies have reported a wide range in the prevalence of constipation in community-dwelling elderly populations (Campbell, Busby, & Horwath, 1993; Chaplin, Curless, Thomson, & Barton, 2000; Hammond, 1964; Wong, Wee, Pin, Gan, & Ye, 1999). Depending on the definition of constipation used, prevalences between 11% and 55% have been reported. Studies using self-defined constipation where participants are free to define constipation themselves without any constraints usually report higher prevalence rates than those using a specified definition or criteria (Wald et al., 2008). A recent US longitudinal study of the general adult population over a period of 20 years
http://dx.doi.org/10.1016/j.archger.2015.02.004 0167-4943/ß 2015 Elsevier Ireland Ltd. All rights reserved.
Please cite this article in press as: Werth, B.L., et al., A longitudinal study of constipation and laxative use in a community-dwelling elderly population. Arch. Gerontol. Geriatr. (2015), http://dx.doi.org/10.1016/j.archger.2015.02.004
G Model
AGG-3131; No. of Pages 7 2
B.L. Werth et al. / Archives of Gerontology and Geriatrics xxx (2015) xxx–xxx
investigated the prevalence of persistent chronic constipation and found that 3% had persistent chronic constipation (Choung et al., 2012) but no longitudinal studies focussed on elderly populations have been published to date. A number of factors associated with an increased risk of constipation have been reported in the general population and one of these risk factors is age. An increase in the prevalence of constipation with age in those older than 60 years has been well documented internationally (Chaplin et al., 2000; Hammond, 1964; Harari, Gurwitz, Avorn, Bohn, & Minaker, 1996; Lu, Chang, Chen, Luo, & Lee, 2006; Nakaji et al., 2002; Wong et al., 1999) with some studies indicating that the largest increases occur after 70–75 years of age (McCrea et al., 2009; Talley, Jones, Nuyts, & Dubois, 2003). In addition to increasing age, other risk factors for constipation identified include gender, co-morbidity and medications. In most studies, females are more likely to report constipation than males (Campbell et al., 1993; Stewart, Moore, Marks, & Hale, 1992; Talley et al., 1996). Other risk factors which have been reported in elderly populations include low levels of physical activity (Brown, Mishra, Lee, & Bauman, 2000), medical conditions such as stress, stroke, heart conditions (Wong et al., 1999) and hemorrhoids (Chiarelli, Brown, & McElduff, 2000), and medications such as diuretics, calcium channel blockers, antidepressants and hypnotics (Campbell et al., 1993; Chiarelli et al., 2000; Wong et al., 1999). Whilst some international studies have reported the prevalence of constipation and risk factors in community-dwelling elderly populations, less is known about the management of constipation and the use of laxatives. Several international studies have reported the prevalence of laxative use in the community-dwelling elderly ranging from 10% to 25% (Campbell et al., 1993; Chaplin et al., 2000; Marfil, Davies, & Dettmar, 2005; May, Stewart, Hale, & Marks, 1982; Pahor, Guralnik, Chrischilles, & Wallace, 1994; Ruby, Fillenbaum, Kuchibhatla, & Hanlon, 2003; Stoehr, Ganguli, Seaberg, Echement, & Belle, 1997; Stoller, 1988; Whitehead, Drinkwater, Cheskin, Heller, & Schuster, 1989). The reported prevalence may vary according to the definition of laxative used, and whether the laxative was prescribed or non-prescribed. U.S. studies have found laxative use to be higher in females than males (May et al., 1982; Stoehr et al., 1997), laxative usage increases with age (Stoehr et al., 1997) and, with the exception of lactulose, all laxative products were over-the-counter (OTC) medicines with few prescribed by doctors (Ruby et al., 2003). However there have been few Australian studies of constipation and laxative use in the community dwelling elderly, and no published Australian study has investigated the association of laxative use with constipation in any population. In fact, the prevalence of laxative use and its association with constipation in the community-dwelling elderly has not been extensively studied either in Australia or internationally, nor have these issues been examined on a longitudinal basis. 2. Objective The aim of our study was to determine the impact of aging on the prevalence of constipation and laxative use in a cohort of community-dwelling elderly residents. We also aimed to explore changes in various risk factors associated with constipation over time. 3. Methods 3.1. Data source The Australian Longitudinal Study of Ageing (ALSA) is a longitudinal cohort study of aging in the community (Luszcz et al., 2007). The study was conducted in Adelaide, South Australia and commenced in 1992 with 2087 participants aged 65 years or
older. Participants were interviewed and data collected at eight different time points over the next 14 years. The number of participants was reduced over this time due to a variety of reasons including refusal to participate further, ill health, death or being un-contactable. The detailed ALSA methodology has been published previously (Luszcz et al., 2007). At baseline in 1992–1993, face-to-face interviews were conducted at the place of residence of each participant to elicit answers to a wide range of questions regarding their health and welfare. Data on all medical conditions were recorded, including self-reported constipation, as well as data for both prescribed and non-prescribed medications. Interviews and collection of data were repeated in 2003–2004. 3.2. Study population Of the original 2087 participants from 1992–1993, 487 participated in 2003–2004, of whom 412 were living in the community and eligible for inclusion in this analysis. For this study, participants must have had complete constipation and medication use data recorded at both the 1992–1993 and 2003–2004 time points. Participants who did not answer the question regarding constipation (n = 30) or who reported a colostomy (n = 3) were excluded from our analysis, as were participants who did not give consent for medication data to be accessed (n = 140), leaving a total of 239 community-dwelling participants with complete constipation and medication use data in both 1992–1993 and 2003–2004. 3.3. Self-reported constipation At both time points, participants were asked to report on constipation. In 1992–1993, the question was: ‘‘Do you often have trouble with your bowels which makes you constipated?’’ and in 2003–2004 participants were asked a slightly different question: ‘‘Do you have trouble with your bowels which makes you constipated?’’. Also at both time points, the participants were asked about bowel movement frequency: ‘‘How often do you usually have a bowel movement?’’. 3.4. Medication use Two sources of medication use data were used. In 1992–1993, participants were asked to name all medications (both prescribed and purchased over-the-counter) which had been taken in the previous two weeks. Participants were also asked to show the medicine container to the interviewer. In 2003–2004, the same methodology was used for OTC medications but they were also asked whether the OTC medicine was prescribed by a doctor. In addition, medicine reimbursement data was obtained for all prescription medicines which had been subsidized by the Australian government. Both reimbursed and OTC medications included a number of laxative agents. 3.5. Potential risk factors for constipation Potential risk factors for constipation were identified from the literature. These included medical conditions, medications and level of physical activity as well as socio-demographic data. Medications were considered to have the potential to cause constipation if listed as an adverse effect in published reviews of the subject (Branch & Butt, 2009; Toney, Wallace, Sekhon, & Agrawal, 2008). Medical conditions associated with constipation identified in the literature included conditions affecting the heart, lower gastrointestinal system (e.g. hemorrhoids), and musculoskeletal system (Chiarelli et al., 2000; Fosnes, Lydersen, & Farup, 2011; Talley et al., 2003; Wong et al., 1999).
Please cite this article in press as: Werth, B.L., et al., A longitudinal study of constipation and laxative use in a community-dwelling elderly population. Arch. Gerontol. Geriatr. (2015), http://dx.doi.org/10.1016/j.archger.2015.02.004
G Model
AGG-3131; No. of Pages 7 B.L. Werth et al. / Archives of Gerontology and Geriatrics xxx (2015) xxx–xxx
3.6. Analysis Analysis of data was done using IBM SPSS Statistics version 21 (IBM Corporation). For unifactorial analyses of potential risk factors, Pearson’s Chi-squared test, Kruskal–Wallis test and t-test (independent and paired) were used as appropriate. Prevalence at each time point was compared using McNemar’s test. P values of 0.05 or less were considered to be statistically significant. 4. Results 4.1. Study population The majority of the cohort was female (61%) and the mean age of the cohort increased from 73 in 1992–1993 to 84 years in 2003– 2004 (Table 1). Half of the cohort had left school by the age of 14 years and a third had some form of post-school qualification. Although the number of medical conditions reported by each participant did not change greatly over the period, the number of medications taken by each participant increased dramatically over time. Physical activity (functional status) as indicated by the activities of daily living (an assessment of basic self-care tasks) declined over the study period as did levels of self-rated health. 4.2. Constipation A statistically significant increase in the prevalence of constipation was seen between 1992–1993 (13.8%) and 2003– 2004 (20.9%) (Table 1). More females than males reported constipation at both time points however the ratio of females to males declined in 2003–2004 (1.51) compared to 1992–1993 (2.42). The change in the female:male prevalence ratio may be attributed to a doubling in the prevalence of constipation in males over the time. Looking at changes over time for individual participants, 64% (n = 21/33) of participants who reported constipation in 1992– 1993 also reported constipation in 2003–2004 (Table 1). These individuals can be classified as persistent sufferers, representing 9% of the total cohort whereas non-persistent cases, those
3
reporting constipation at one time point only, represented 18% of the total cohort with 73% not reporting constipation at either time point. The frequency of bowel motions did not correlate with selfreported constipation at either time point. Only 12% (n = 4/33) of those reporting constipation in 1992–1993 also reported 3 or fewer bowel motions per week, and in 2003–2004 this figure was 14% (n = 7/50). There was no significant difference in bowel motion frequency between the two time points. Potential risk factors varied between the 1992–1993 and 2003– 2004 time periods (Table 2). Risk factors which were significantly associated with self-reported constipation at both time points included the level of physical activity/functional status, as measured by the activities of daily living (ADL), and the number of medical conditions reported by participants. Also those who reported their health as poor or fair were more likely to report constipation at both time points. In 1992–1993, participants with a post-school qualification were less likely to report constipation and the age at which participants left school was also significant but neither of these factors remained significant in 2003–2004. Certain medical conditions have been reported in the literature as being frequently associated with constipation and these were investigated (Table 2). No significant differences were found in 1992–1993 with regard to constipation and specified co-morbidities with the exception of osteoporosis, however this changed over time. In the 2003–2004 data, heart conditions (including angina), arthritis, hemorrhoids, osteoporosis and muscular complaints were all significant risk factors for constipation. Medication use varied over time. The number of medications used was significantly associated with self-reported constipation in 1992–1993, however despite the number of medications per participant increasing over time, no association between number of medications and self-reported constipation was observed at the second time point (Table 2). Tricyclic antidepressants were the only drugs significantly associated with constipation at both times; other drugs significantly associated with constipation at one time point were diuretics, non-steroidal anti-inflammatory drugs (NSAIDs), opioid analgesics, anti-parkinsonism drugs and clonidine.
Table 1 Participant characteristics, including self-reported constipation (SRC), bowel motions (BM) and laxative use (LU). Characteristic
1992–1993
2003–2004
Mean age (years) Age range (years) Females, n (% of total) Age left school (
