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International Journal of Nursing Practice 2014; ••: ••–••
COCHRANE NURSING CARE NETWORK
Overview of reviews: Mechanical interventions for the treatment and management of chronic obstructive pulmonary disease Karolina Lisy BSc (Hons) PhD The Joanna Briggs Institute, The School of Translational Health Science, The University of Adelaide, Adelaide, South Australia, Australia The Cochrane Nursing Care Field, Cochrane Collaboration, Adelaide, South Australia, Australia
Heath White BBiotech (Hons) The Joanna Briggs Institute, The School of Translational Health Science, The University of Adelaide, Adelaide, South Australia, Australia The Cochrane Nursing Care Field, Cochrane Collaboration, Adelaide, South Australia, Australia
Alan Pearson RN PhD FRCNA FAAG FRCN AM The Joanna Briggs Institute, The School of Translational Health Science, The University of Adelaide, Adelaide, South Australia, Australia The Cochrane Nursing Care Field, Cochrane Collaboration, Adelaide, South Australia, Australia
Accepted for publication November 2013 Lisy K, White H, Pearson A. International Journal of Nursing Practice 2014; ••: ••–•• Overview of reviews: Mechanical interventions for the treatment and management of chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease (COPD) is characterized by a progressive and non-reversible airflow limitation and symptoms of breathlessness, sputum production and cough. COPD is the fourth most common cause of mortality worldwide and represents a significant social and economic burden. As such, effective strategies that might be employed to treat COPD and manage symptoms need to be investigated. This overview aimed to summarize the existing evidence available in the Cochrane Library regarding the use of mechanical interventions used for the treatment and management of COPD. Systematic reviews that included adult participants with diagnosed COPD who received a mechanical intervention were included. Five reviews were included, and due to the heterogeneity of these reviews, direct and indirect comparisons of the effects of the intervention were not possible. Instead, data of the effectiveness of each intervention were extracted and summarized in tables and discussed as a narrative summary. Interventions included non-invasive positive pressure ventilation (NPPV), positive airway pressure (PEP) devices and neuromuscular electrical stimulation (NMES). Evidence regarding the effectiveness of NPPV was limited, and available data do not support the use of NPPV for patients with stable COPD. NPPV might, however, be of benefit as a weaning strategy for intubated patients and for patients experiencing respiratory failure; however, more research is required. Although PEP devices are considered as a safe airway clearance technique, data do not reveal a clear clinical benefit to their use. NMES is also regarded as safe for
Correspondence: Karolina Lisy, The Joanna Briggs Institute, The School of Translational Health Science, The University of Adelaide, 115 Grenfell Street, Adelaide, SA 5000, Australia. Email: [email protected] doi:10.1111/ijn.12303
© 2014 Wiley Publishing Asia Pty Ltd
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patients with COPD, and might also be beneficial in improving exercise tolerance and improving quality of life for patients with COPD. Key words: COPD, mechanical, overview.
INTRODUCTION Background Description of the condition Chronic obstructive pulmonary disease (COPD) is classified as being a chronic respiratory disease characterized as a progressive airflow limitation with symptoms of dyspnoea, cough and sputum production.1 The World Health Organization estimated that 64 million people worldwide had COPD in 2004, and that COPD caused 3 million deaths, or 5% of all deaths worldwide in 2005.2 Most deaths due to COPD occur in low and middleincome countries, with morbidity and mortality arising from COPD expected to rise in these countries due to increases in the prevalence of known risk factors such as air pollution and smoking.2 Indoor air pollution caused by household use of solid fuels such as wood and coal is the main risk factor for COPD in low-income countries, whereas smoking is the major COPD risk factor in highincome countries. Other risk factors for COPD include frequent upper respiratory infections during childhood, occupational inhalation of chemicals and dusts, and genetic deficiency of normal alpha-1 antitrypsin.3 COPD is preventable and treatable, but not curable. In addition to the respiratory symptoms, extrapulmonary effects such as muscle wasting and decreased fat-free mass also frequently occur in COPD patients.4 Patients with COPD will also experience acute exacerbations of these symptoms that might require hospital admission. Effective management strategies are required to prolong life and minimize or reduce symptoms for COPD sufferers. Current management plans are aimed at reducing risk factors, controlling symptoms, preventing complications, and reducing the number and severity of exacerbations.5 Treatments are often multifaceted and complex, and can include one or more of the following: pharmaceutical interventions including bronchodilators, steroids or antibiotics; oxygen therapy; surgical interventions; device-based interventions such as ventilation; and pulmonary rehabilitation strategies such as exercise programmes, changes to diet, breathing strategies and education. This review will focus exclusively on device-based interventions for COPD management. © 2014 Wiley Publishing Asia Pty Ltd
Description of the interventions Non-invasive positive pressure ventilation. Non-invasive positive pressure ventilation (NPPV) provides ventilatory support for patients with a severe impairment.6,7 NPPV is defined as any form of positive ventilator support without the use of an endotracheal tube, usually administered via nose or face mask, often at night, on a regular basis. It is thought to benefit COPD patients by allowing chronically fatigued respiratory muscles time to rest and recover and also by enabling patients to achieve higherquality sleep. Neuromuscular electrical stimulation. Individuals with COPD might experience muscle wasting and weakness, which negatively impacts on exercise performance and therefore contributes to poorer health status. Neuromuscular electrical stimulation (NMES) is delivered via a battery-operated device which sends electrical impulses to muscles via electrodes placed on the skin. The impulses act to mimic the electrical signal received by muscles from the central nervous system, and causes the muscles to contract. NMES might assist in improving muscle strength in individuals unable or unwilling to adhere to exercise regimens,8 and this might improve exercise capacity and quality of life. Positive expiratory pressure device therapy. Positive expiratory pressure (PEP) devices provide resistance to exhalation and are used to dilate the airways and improve mucous clearance.9 Some PEP devices combine PEP with oscillation to transmit vibrations through the airways and facilitate mucous expectoration.10
Why it is important to do this overview There are a variety of interventions used for the management and treatment of COPD. Scrutiny of current treatment methods is important to enable identification of the most effective methods that improve outcomes for patients. It is also important that the most effective management and treatment strategies be determined, as optimal management of the disease could reduce exacerbations and potentially decrease doctor and hospital visits,
Chronic obstructive disease interventions
reducing the significant burden of COPD on health-care systems.
Objectives The objective of this review is to summarize evidence from Cochrane systematic reviews on the effectiveness of device-based interventions for the treatment and management of COPD.
METHODS Inclusion criteria Types of participants This overview included adult participants over 18 years of age diagnosed with COPD (as defined by review authors) who received any devise-based/mechanical intervention for the treatment and/or management for COPD and/or exacerbations of COPD.
Types of interventions Interventions considered were any device-based intervention administered with the aim treating or managing COPD. This included NPPV, NMES, PEP devices and oscillatory devices. Interventions were compared with either no treatment, sham treatment or standard care, as described in each study in the included reviews. Standard care included any usual care, including the use of supplemental oxygen, antibiotics, bronchodilators, steroids, respiratory stimulants. Reviews that examined nonmechanical interventions, such as surgical interventions, pharmacological interventions or exercise-based interventions, were excluded.
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• lung function (measured by either forced expiratory volume (FEV1) or forced vital capacity (FVC)) arterial partial pressure of oxygen (PaO2) and/or carbon dioxide (PaCO2) dyspnoea endurance/exercise capacity (6 min walk test or other) sleep quality adherence to programme health-related quality of life (HRQoL) Secondary outcomes will include any complications or adverse events arising from treatment.
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Search strategy The Cochrane Database of Systematic Reviews on The Cochrane Library was searched in April 2013 using: the search term COPD in the title, keywords or abstract the MeSH descriptor Pulmonary Disease, Chronic Obstructive explode all trees The MeSH descriptor Lung Diseases, Obstructive, this term only (#1 or #2 or #3)
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Data collection and analysis Selection of reviews We included all completed and updated Cochrane systematic reviews of mechanical or device-based interventions for the management or treatment of COPD. Three authors (AP, HW and KL) reviewed the search results by title and abstract, and retrieved full-text articles for reviews deemed as relevant for this overview.
Types of studies This overview included Cochrane systematic reviews of randomized controlled trials (RCTs) or quasi-RCTs that examined devise-based methods of treatment and management of COPD and/or exacerbations of COPD. Other systematic reviews or health technology assessment reports produced external to the Cochrane collaboration were not considered for inclusion.
Types of outcomes Primary outcomes might include the following, depending on the outcomes measured in the included reviews. mortality hospital admissions hospital length of stay Intensive care unit (ICU) length of stay (LOS)
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Assessment of methodological quality of included reviews Two authors (HW and KL) independently assessed the methodological quality of the studies selected for retrieval using the Joanna Briggs Institute Critical Appraisal Tool for Systematic Reviews (Appendix SI). This tool uses the following appraisal criteria: 1. Is the review question clearly and explicitly stated? 2. Was the search strategy appropriate? 3. Were the sources of studies adequate? 4. Were the inclusion criteria appropriate for the review question? 5. Were the criteria for appraising studies appropriate? 6. Was critical appraisal conducted by two or more reviewers independently? © 2014 Wiley Publishing Asia Pty Ltd
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7. Were there methods used to minimize errors in data extraction? 8. Were the methods used to combine studies appropriate? 9. Were the recommendations supported by the reported data? 10. Were the specific directives for new research appropriate? Any discrepancies were resolved by discussion.
Data extraction and management Two authors (HW and KL) independently extracted data from the included reviews using a predefined data extraction table (Appendix SII). Any disagreements were resolved by discussion or by the third reviewer (AP).
Data synthesis Data collected from included reviews and studies are presented in tables and discussed in narrative summary. Due to the heterogeneity of the included systematic reviews, it was not possible to directly or indirectly compare the effects of interventions for this overview.
RESULTS Description of included reviews Five Cochrane systematic reviews were included in this overview: Burns et al.,11 Maddocks et al.,12 Osadnik et al.,13 Ram et al.14 and Wijkstra et al.15 (Fig. 1; Table A1 (Appendix SIII)). The search returned 156 results which were screened by title. The abstracts of 13 reviews were
then screened and six reviews were identified as being potentially relevant. The full text for these six reviews was retrieved and one review was excluded as it did not involve participants with COPD. The characteristics of each included review are presented in Table A1 (Appendix SIII).
Methodological quality of included reviews Two authors (KL and HW) independently assessed the methodological quality of each review according to prespecified criteria. The included reviews were all found to be of high quality and all were included in the overview. All included reviews explicitly and clearly stated the objectives of the review. Inclusion criteria were appropriate. The search strategies and sources of studies included in each review were deemed appropriate and adequate, and critical appraisal was stated to have been conducted by two reviewers in four out of five studies, excluding Wijkstra et al.15 Data extraction errors were minimized in four out of five studies by either performing random accuracy checks (Osadnik et al.13) or two authors independently extracting data (Burns et al.,11 Maddocks et al.12 and Ram et al.14). Wijkstra et al.15 did not specify how errors in data extraction were minimized. Meta-analyses were conducted where possible, and statistical methods used to analyse data were appropriate. Authors’ implications for practice and research were considered to be congruent with the evidence presented in each review.
Quality of evidence in included reviews Four of the systematic reviews included in this overview assessed the risk of bias of studies using the Cochrane approach that addresses six potential sources of bias: sequence generation, allocation concealment, blinding of study participants and personnel, completeness of outcome data selective reporting, and other sources of bias. Wijkstra et al.15 used the Jadad scale, and Ram et al.14 used both the Cochrane risk of bias assessment tool and the Jadad scale.
Effects of the interventions
Figure 1. Study selection flow chart.
© 2014 Wiley Publishing Asia Pty Ltd
The outcomes of the studies in the included reviews are presented in Appendix SIV. Due to the heterogeneity of the included systematic reviews, it was not possible to directly compare the effects of each intervention. Here, the effects of each intervention on the outcomes of interest to this overview will be described.
Chronic obstructive disease interventions
NPPV Three reviews investigated the effectiveness of NPPV as a method of treating patients with COPD.11,14,15 One review focused on the use of NPPV as a weaning strategy for intubated patients11; another on the use of NPPV for treatment of respiratory failure for patients experiencing an acute exacerbation of COPD14; and lastly the use of nocturnal NPPV for treatment of COPD patients.15
NPPV for weaning intubated patients: Burns et al.11 Pooling of results from eight studies that included only patients with COPD provided strong evidence that NPPV weaning reduced mortality of intubated adults compared with invasive weaning (RR 0.42, 95% CI 0.25, 0.69). Ten trials with a total of 485 patients (seven exclusively COPD; 344 participants, three mixed population; 141 participants) showed a significant benefit for the use of NPPV weaning compared with invasive positive pressure ventilation (IPPV) for ICU LOS (weighted mean difference (WMD) −6.27, 95% CI −8.77, −3.78). There was also a significant benefit for hospital LOS (WMD −7.19, 95% CI −10.80, −3.38) observed when data from eight studies with a total of 401 patients (five exclusively COPD; 260 participants, three mixed populations; 141 participants).
NPPV for respiratory failure during exacerbations of COPD: Ram et al14 Ten studies (622 participants) reported on mortality and found a significant decrease in mortality with NPPV compared with standard care (RR 0.52, 95% CI 0.35, 0.76). Hospital LOS was reported in eight studies (546 patients) and found to be significantly shorter (WMD −3.24 days, 95% CI −4.42, −2.06 days) with NPPV, and although there was a trend towards shorted stay in the ICU, this was not found to be statistically significant. Data from five and four studies were used for meta-analysis of PaCO2 and PaO2 1 h following NPPV. PaCO2 improved (WMD −0.40 kPa, 95% CI −0.78, −0.03); however, PaO2 did not significantly increase.
Nocturnal NPPV for stable COPD: Wijkstra et al.15 There was no change in reported FEV1 or FVC between nocturnal NPPV and the control (four studies each, total of 67 participants). Although non-significant, metaanalysis of data from four studies and 67 participants showed small differences in PaO2 and PaCO2 that favoured NPPV. Exercise tolerance, measured by the 6 min walk test, was improved in two studies; however,
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this result was not significant. Sleep efficiency was found to be non-significantly decreased with NPPV when the data from three studies were combined.
Neuromuscular stimulation: Maddocks et al.12 Subgroup analysis for COPD patients was not performed; however, there were significant benefits to NMES found for both quadriceps muscle strength (standardised mean difference 0.90, 95% CI 0.33, 1.46; eight studies) and exercise performance demonstrated using three different tests; 6 min walk test (mean difference (MD) 40.05 m, 95% CI −4.14, 84.24 m; four studies), incremental shuttle walk test (MD 68.80 m, 95% CI 18.54, 119.06 m; one study) and endurance shuttle walk test (SD 160.22 m, 95% CI 33.73, 286.70 m; two studies). Two studies found improvements in self-reported breathlessness following an NMES programme (data not given), and three studies indicated improvements in overall HRQoL for patients who received NMES (data not given).
PEP device airway clearance technique: Osadnik et al.13 Outcome data were separated for acute exacerbations of COPD and stable COPD. For patients suffering exacerbations of COPD, hospital LOS was significantly reduced in the one study using PEP techniques that assessed this outcome (MD −1.10, 95% CI −1.89, −0.31; 33 participants). Lung function outcomes (FEV1 and FEV1/FVC (%)) were not significantly improved with the use of PEP airway clearance techniques compared with when no airway clearance technique was used in one study of 27 participants. PEP techniques did not significantly affect PaO2 or PaCO2 according to one study of 26 participants. There was not a significant difference in mortality between PEP airway clearance techniques and no airway clearance techniques groups. For patients with stable COPD, there was no significant difference in the total number of days in hospital; however, there was a significant decrease in the number of respiratory hospital admissions with the use of PEP devices (OR 0.27, 95% CI 0.08, 0.95; one study, 50 participants). The results regarding pulmonary function were generally small and inconsistent. Immediate FEV1 was slightly improved by PEP compared with no airway clearance technique (MD 0.04, 95% CI 0.00, 0.07; 23 participants), and no improvement on short-term FEV1 (two studies, 118 participants). No differences in gas exchange were observed between experimental and © 2014 Wiley Publishing Asia Pty Ltd
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control groups (one study, 90 participants). One study of 15 participants assessed the effect of PEP devices compared with a sham intervention on HRQoL measured by the St George’s Respiratory Questionnaire. The results favoured the intervention (MD −6.10, 95% CI −8.93 to −3.27). The same study also measured breathlessness and found a significant improvement (MD −0.30, 95% CI −0.53, −0.07) according to self-reports from 23 participants. Benefits of PEP device therapy were also reported for both short-term and long-term exercise tolerance. Short-term exercise tolerance as measured by the 6 min walk test improved significantly (MD 12.93, 95% CI 5.98, 19.98; 2 studies, 38 participants), and long-term exercise as measured by 12 min walk test also improved according to one study (MD 111.00, 95% CI 66.46, 155.54). There were no data for mortality for patients with stable COPD using PEP devices.
DISCUSSION Summary of main results The included reviews all investigated the effectiveness in the treatment and management of device-based therapies used in the treatment and management of COPD. Five reviews covering NPPV, nocturnal NPPV, PEP devices and NMES were included in this overview. Data from high-quality RCTs indicate that NPPV might be used in addition to standard care in the treatment of patients with acute respiratory failure due to exacerbations of COPD. Results show that NPPV decreased mortality and hospital LOS and improved respiratory rate. NPPV could also be beneficial as a weaning strategy for intubated patients with respiratory failure, with results from clinical trials showing significant reductions in mortality and hospital and ICU LOS. No study reported on QoL outcomes, and further evidence from larger samples sizes is needed before this strategy can be recommended for use in this patient group. Nocturnal NPPV for 3 months did not show significant effects on pulmonary function, gas exchange or exercise capacity. Though non-significant, there was a trend towards decreased sleep efficiency. Overall, the data do not support the use of nocturnal NPPV for the treatment of individuals with COPD at present; however, the small overall sample size precluded a definitive conclusion. Evidence regarding the use of PEP airway clearance techniques did not support their use in the treatment of patients with COPD. PEP techniques were deemed to be safe, but did not significantly or clinically benefit patients © 2014 Wiley Publishing Asia Pty Ltd
according to majority of the outcome measures reported on. There were some benefits seen for patients with stable COPD related to reduced hospital admissions, improved exercise ability and improvements in self-reported breathlessness and QoL; however, most of these data came from single studies with small sample sizes. NMES programmes were found to be effective for patients with COPD in managing muscle weakness and improving exercise tolerance, though the latter result only showed a moderate improvement that has questionable clinical significance. Symptoms of breathlessness (self-reported) were also found to be improved, and overall HRQoL was found to improve in three studies. Moreover, NMES was found to be a safe intervention and particularly suitable for those patients who were unable to participate in traditional exercise programmes.
Overall completeness and applicability of the evidence This overview aimed to determine the effectiveness of device and mechanical interventions used in the treatment and management of COPD, exacerbations of COPD and respiratory failure due to COPD. The review includes completed and recently updated Cochrane reviews, and the evidence report is therefore considered to be up to date and current. The included systematic reviews all involved participants with COPD, and where populations were mixed, only data pertaining to patients with COPD were extracted. Due to the heterogeneity of the participants and interventions between the systematic reviews, it was not possible to directly or indirectly compare the effects of the different interventions.
AUTHORS’ CONCLUSIONS Implications for practice Overall, the implications for practice based on the evidence presented for each intervention are the following: PEP device airway clearance techniques are safe but of limited clinical value. Such devices might have greater benefit for patients with acute exacerbations of COPD, but there is no clear evidence for benefits of this strategy for individuals with stable COPD. NMES regimens are safe and effective interventions for combating muscle weakness in patients with COPD, and might provide a benefit for exercise tolerance, symptoms of breathlessness and quality of life. NMES could be of particular benefit for patients who are unable to participate or maintain other forms of exercise.
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Chronic obstructive disease interventions
• There is no evidence to recommend the use of noctur•
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nal NPPV for patients with stable COPD; however, the evidence base for this intervention was limited by the small overall sample size. NPPV appears to be a preferable weaning strategy compared with IPPV for intubated patients with respiratory failure; however, the evidence is currently not sufficient to warrant formal recommendations for use of this strategy in practice. Data suggest that NPPV might be recommended as an adjunct therapy to usual medical care for management of patients with respiratory failure due to an acute exacerbation of COPD, where appropriate; however, further studies regarding selection of patients suitable for this strategy are needed.
Implications for research Further research is needed surrounding the use of all interventions covered in this overview, and is particularly warranted given the significant social and economic burdens of COPD worldwide. In particular: Additional RCTs are needed for the assessment of nocturnal NPPV as the existing evidence base is too small to draw meaningful conclusions from. Future studies on PEP airway clearance techniques would be strengthened if there was consistency in outcome measures used in studies, as many outcomes were informed by only one study. Although the evidence regarding NPPV as a weaning strategy for intubated patients is encouraging, a welldesigned and adequately powered RCT is needed to directly investigate the effectiveness of this strategy compared with other approaches to weaning. Any future work surrounding NMES for COPD patients should focus on defining optimal parameters for treatment programmes, identification of patients most likely to benefit from NMES programmes, and should include other outcome measures such as mortality and hospitalization events. Similarly, more data are needed regarding patients with acute exacerbations of COPD and respiratory failure that would be suitable for NPPV treatment. The feasibility, safety and effectiveness of this approach need to be explored in different settings, and the use of NPPV as an alternative to intubation for patients with respiratory failure should also be investigated.
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CONFLICT OF INTEREST None to declare.
REFERENCES 1 Rycroft CE, Heyes A, Lanza L, Becker K. Epidemiology of chronic obstructive pulmonary disease: A literature review. International Journal of Chronic Obstructive Pulmonary Disease 2012; 7: 457–494. 2 Organisation WH. Global surveillance, prevention and control of chronic respiratory diseases: a comprehensive approach. 2007. 3 Stoller JK, Aboussouan LS. Alpha1-antitrypsin deficiency. The Lancet 2005; 365: 2225–2236. 4 Agusti AG. Systemic effects of chronic obstructive pulmonary disease. Proceedings of the American Thoracic Society 2005; 2: 367–370; discussion 71–72. 5 Rabe KF, Hurd S, Anzueto A et al. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. American Journal of Respiratory and Critical Care Medicine 2007; 176: 532–555. 6 Brochard L. Non-invasive ventilation for acute exacerbations of COPD: A new standard of care. Thorax 2000; 55: 817–818. 7 Brochard L, Mancebo J, Wysocki M et al. Noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease. The New England Journal of Medicine 1995; 333: 817–822. 8 Dehail P, Duclos C, Barat M. Electrical stimulation and muscle strengthening. Annales de Readaptation et de Medecine Physique 2008; 51: 441–451. 9 Langenderfer B. Alternatives to percussion and postural drainage. A review of mucus clearance therapies: Percussion and postural drainage, autogenic drainage, positive expiratory pressure, flutter valve, intrapulmonary percussive ventilation, and high-frequency chest compression with the ThAIRapy Vest. Journal of Cardiopulmonary Rehabilitation 1998; 18: 283–289. 10 Volsko TA, DiFiore J, Chatburn RL. Performance comparison of two oscillating positive expiratory pressure devices: Acapella versus Flutter. Respiratory Care 2003; 48: 124– 130. 11 Burns KE, Adhikari NK, Keenan SP, Meade MO. Noninvasive positive pressure ventilation as a weaning strategy for intubated adults with respiratory failure. Cochrane Database of Systematic Reviews 2010; (8): CD004127. 12 Maddocks M, Gao W, Higginson IJ, Wilcock A. Neuromuscular electrical stimulation for muscle weakness in adults with advanced disease. Cochrane Database of Systematic Reviews 2013; (1): CD009419. 13 Osadnik CR, McDonald CF, Jones AP, Holland AE. Airway clearance techniques for chronic obstructive pulmonary © 2014 Wiley Publishing Asia Pty Ltd
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disease. Cochrane Database of Systematic Reviews 2012; (3): CD008328. 14 Ram FS, Picot J, Lightowler J, Wedzicha JA. Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews 2004; (3): CD004104. 15 Wijkstra PJ, Lacasse Y, Guyatt GH, Goldstein RS. Nocturnal non-invasive positive pressure ventilation for stable chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews 2002; (3): CD002878.
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SUPPORTING INFORMATION Additional Supporting Information may be found in the online version of this article at the publisher’s web-site: Appendix Appendix Appendix Appendix reviews.
SI Critical appraisal instrument. SII Data extraction instrument. SIII Characteristics of included reviews. SIV Summary of evidence from included
International Journal of Nursing Practice 2014; ••: ••–••
COCHRANE NURSING CARE NETWORK
Overview of reviews: Mechanical interventions for the treatment and management of chronic obstructive pulmonary disease Karolina Lisy BSc (Hons) PhD The Joanna Briggs Institute, The School of Translational Health Science, The University of Adelaide, Adelaide, South Australia, Australia The Cochrane Nursing Care Field, Cochrane Collaboration, Adelaide, South Australia, Australia
Heath White BBiotech (Hons) The Joanna Briggs Institute, The School of Translational Health Science, The University of Adelaide, Adelaide, South Australia, Australia The Cochrane Nursing Care Field, Cochrane Collaboration, Adelaide, South Australia, Australia
Alan Pearson RN PhD FRCNA FAAG FRCN AM The Joanna Briggs Institute, The School of Translational Health Science, The University of Adelaide, Adelaide, South Australia, Australia The Cochrane Nursing Care Field, Cochrane Collaboration, Adelaide, South Australia, Australia
Accepted for publication November 2013 Lisy K, White H, Pearson A. International Journal of Nursing Practice 2014; ••: ••–•• Overview of reviews: Mechanical interventions for the treatment and management of chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease (COPD) is characterized by a progressive and non-reversible airflow limitation and symptoms of breathlessness, sputum production and cough. COPD is the fourth most common cause of mortality worldwide and represents a significant social and economic burden. As such, effective strategies that might be employed to treat COPD and manage symptoms need to be investigated. This overview aimed to summarize the existing evidence available in the Cochrane Library regarding the use of mechanical interventions used for the treatment and management of COPD. Systematic reviews that included adult participants with diagnosed COPD who received a mechanical intervention were included. Five reviews were included, and due to the heterogeneity of these reviews, direct and indirect comparisons of the effects of the intervention were not possible. Instead, data of the effectiveness of each intervention were extracted and summarized in tables and discussed as a narrative summary. Interventions included non-invasive positive pressure ventilation (NPPV), positive airway pressure (PEP) devices and neuromuscular electrical stimulation (NMES). Evidence regarding the effectiveness of NPPV was limited, and available data do not support the use of NPPV for patients with stable COPD. NPPV might, however, be of benefit as a weaning strategy for intubated patients and for patients experiencing respiratory failure; however, more research is required. Although PEP devices are considered as a safe airway clearance technique, data do not reveal a clear clinical benefit to their use. NMES is also regarded as safe for
Correspondence: Karolina Lisy, The Joanna Briggs Institute, The School of Translational Health Science, The University of Adelaide, 115 Grenfell Street, Adelaide, SA 5000, Australia. Email: [email protected] doi:10.1111/ijn.12303
© 2014 Wiley Publishing Asia Pty Ltd
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K Lisy et al.
patients with COPD, and might also be beneficial in improving exercise tolerance and improving quality of life for patients with COPD. Key words: COPD, mechanical, overview.
INTRODUCTION Background Description of the condition Chronic obstructive pulmonary disease (COPD) is classified as being a chronic respiratory disease characterized as a progressive airflow limitation with symptoms of dyspnoea, cough and sputum production.1 The World Health Organization estimated that 64 million people worldwide had COPD in 2004, and that COPD caused 3 million deaths, or 5% of all deaths worldwide in 2005.2 Most deaths due to COPD occur in low and middleincome countries, with morbidity and mortality arising from COPD expected to rise in these countries due to increases in the prevalence of known risk factors such as air pollution and smoking.2 Indoor air pollution caused by household use of solid fuels such as wood and coal is the main risk factor for COPD in low-income countries, whereas smoking is the major COPD risk factor in highincome countries. Other risk factors for COPD include frequent upper respiratory infections during childhood, occupational inhalation of chemicals and dusts, and genetic deficiency of normal alpha-1 antitrypsin.3 COPD is preventable and treatable, but not curable. In addition to the respiratory symptoms, extrapulmonary effects such as muscle wasting and decreased fat-free mass also frequently occur in COPD patients.4 Patients with COPD will also experience acute exacerbations of these symptoms that might require hospital admission. Effective management strategies are required to prolong life and minimize or reduce symptoms for COPD sufferers. Current management plans are aimed at reducing risk factors, controlling symptoms, preventing complications, and reducing the number and severity of exacerbations.5 Treatments are often multifaceted and complex, and can include one or more of the following: pharmaceutical interventions including bronchodilators, steroids or antibiotics; oxygen therapy; surgical interventions; device-based interventions such as ventilation; and pulmonary rehabilitation strategies such as exercise programmes, changes to diet, breathing strategies and education. This review will focus exclusively on device-based interventions for COPD management. © 2014 Wiley Publishing Asia Pty Ltd
Description of the interventions Non-invasive positive pressure ventilation. Non-invasive positive pressure ventilation (NPPV) provides ventilatory support for patients with a severe impairment.6,7 NPPV is defined as any form of positive ventilator support without the use of an endotracheal tube, usually administered via nose or face mask, often at night, on a regular basis. It is thought to benefit COPD patients by allowing chronically fatigued respiratory muscles time to rest and recover and also by enabling patients to achieve higherquality sleep. Neuromuscular electrical stimulation. Individuals with COPD might experience muscle wasting and weakness, which negatively impacts on exercise performance and therefore contributes to poorer health status. Neuromuscular electrical stimulation (NMES) is delivered via a battery-operated device which sends electrical impulses to muscles via electrodes placed on the skin. The impulses act to mimic the electrical signal received by muscles from the central nervous system, and causes the muscles to contract. NMES might assist in improving muscle strength in individuals unable or unwilling to adhere to exercise regimens,8 and this might improve exercise capacity and quality of life. Positive expiratory pressure device therapy. Positive expiratory pressure (PEP) devices provide resistance to exhalation and are used to dilate the airways and improve mucous clearance.9 Some PEP devices combine PEP with oscillation to transmit vibrations through the airways and facilitate mucous expectoration.10
Why it is important to do this overview There are a variety of interventions used for the management and treatment of COPD. Scrutiny of current treatment methods is important to enable identification of the most effective methods that improve outcomes for patients. It is also important that the most effective management and treatment strategies be determined, as optimal management of the disease could reduce exacerbations and potentially decrease doctor and hospital visits,
Chronic obstructive disease interventions
reducing the significant burden of COPD on health-care systems.
Objectives The objective of this review is to summarize evidence from Cochrane systematic reviews on the effectiveness of device-based interventions for the treatment and management of COPD.
METHODS Inclusion criteria Types of participants This overview included adult participants over 18 years of age diagnosed with COPD (as defined by review authors) who received any devise-based/mechanical intervention for the treatment and/or management for COPD and/or exacerbations of COPD.
Types of interventions Interventions considered were any device-based intervention administered with the aim treating or managing COPD. This included NPPV, NMES, PEP devices and oscillatory devices. Interventions were compared with either no treatment, sham treatment or standard care, as described in each study in the included reviews. Standard care included any usual care, including the use of supplemental oxygen, antibiotics, bronchodilators, steroids, respiratory stimulants. Reviews that examined nonmechanical interventions, such as surgical interventions, pharmacological interventions or exercise-based interventions, were excluded.
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• lung function (measured by either forced expiratory volume (FEV1) or forced vital capacity (FVC)) arterial partial pressure of oxygen (PaO2) and/or carbon dioxide (PaCO2) dyspnoea endurance/exercise capacity (6 min walk test or other) sleep quality adherence to programme health-related quality of life (HRQoL) Secondary outcomes will include any complications or adverse events arising from treatment.
• • • • • •
Search strategy The Cochrane Database of Systematic Reviews on The Cochrane Library was searched in April 2013 using: the search term COPD in the title, keywords or abstract the MeSH descriptor Pulmonary Disease, Chronic Obstructive explode all trees The MeSH descriptor Lung Diseases, Obstructive, this term only (#1 or #2 or #3)
• • • •
Data collection and analysis Selection of reviews We included all completed and updated Cochrane systematic reviews of mechanical or device-based interventions for the management or treatment of COPD. Three authors (AP, HW and KL) reviewed the search results by title and abstract, and retrieved full-text articles for reviews deemed as relevant for this overview.
Types of studies This overview included Cochrane systematic reviews of randomized controlled trials (RCTs) or quasi-RCTs that examined devise-based methods of treatment and management of COPD and/or exacerbations of COPD. Other systematic reviews or health technology assessment reports produced external to the Cochrane collaboration were not considered for inclusion.
Types of outcomes Primary outcomes might include the following, depending on the outcomes measured in the included reviews. mortality hospital admissions hospital length of stay Intensive care unit (ICU) length of stay (LOS)
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Assessment of methodological quality of included reviews Two authors (HW and KL) independently assessed the methodological quality of the studies selected for retrieval using the Joanna Briggs Institute Critical Appraisal Tool for Systematic Reviews (Appendix SI). This tool uses the following appraisal criteria: 1. Is the review question clearly and explicitly stated? 2. Was the search strategy appropriate? 3. Were the sources of studies adequate? 4. Were the inclusion criteria appropriate for the review question? 5. Were the criteria for appraising studies appropriate? 6. Was critical appraisal conducted by two or more reviewers independently? © 2014 Wiley Publishing Asia Pty Ltd
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7. Were there methods used to minimize errors in data extraction? 8. Were the methods used to combine studies appropriate? 9. Were the recommendations supported by the reported data? 10. Were the specific directives for new research appropriate? Any discrepancies were resolved by discussion.
Data extraction and management Two authors (HW and KL) independently extracted data from the included reviews using a predefined data extraction table (Appendix SII). Any disagreements were resolved by discussion or by the third reviewer (AP).
Data synthesis Data collected from included reviews and studies are presented in tables and discussed in narrative summary. Due to the heterogeneity of the included systematic reviews, it was not possible to directly or indirectly compare the effects of interventions for this overview.
RESULTS Description of included reviews Five Cochrane systematic reviews were included in this overview: Burns et al.,11 Maddocks et al.,12 Osadnik et al.,13 Ram et al.14 and Wijkstra et al.15 (Fig. 1; Table A1 (Appendix SIII)). The search returned 156 results which were screened by title. The abstracts of 13 reviews were
then screened and six reviews were identified as being potentially relevant. The full text for these six reviews was retrieved and one review was excluded as it did not involve participants with COPD. The characteristics of each included review are presented in Table A1 (Appendix SIII).
Methodological quality of included reviews Two authors (KL and HW) independently assessed the methodological quality of each review according to prespecified criteria. The included reviews were all found to be of high quality and all were included in the overview. All included reviews explicitly and clearly stated the objectives of the review. Inclusion criteria were appropriate. The search strategies and sources of studies included in each review were deemed appropriate and adequate, and critical appraisal was stated to have been conducted by two reviewers in four out of five studies, excluding Wijkstra et al.15 Data extraction errors were minimized in four out of five studies by either performing random accuracy checks (Osadnik et al.13) or two authors independently extracting data (Burns et al.,11 Maddocks et al.12 and Ram et al.14). Wijkstra et al.15 did not specify how errors in data extraction were minimized. Meta-analyses were conducted where possible, and statistical methods used to analyse data were appropriate. Authors’ implications for practice and research were considered to be congruent with the evidence presented in each review.
Quality of evidence in included reviews Four of the systematic reviews included in this overview assessed the risk of bias of studies using the Cochrane approach that addresses six potential sources of bias: sequence generation, allocation concealment, blinding of study participants and personnel, completeness of outcome data selective reporting, and other sources of bias. Wijkstra et al.15 used the Jadad scale, and Ram et al.14 used both the Cochrane risk of bias assessment tool and the Jadad scale.
Effects of the interventions
Figure 1. Study selection flow chart.
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The outcomes of the studies in the included reviews are presented in Appendix SIV. Due to the heterogeneity of the included systematic reviews, it was not possible to directly compare the effects of each intervention. Here, the effects of each intervention on the outcomes of interest to this overview will be described.
Chronic obstructive disease interventions
NPPV Three reviews investigated the effectiveness of NPPV as a method of treating patients with COPD.11,14,15 One review focused on the use of NPPV as a weaning strategy for intubated patients11; another on the use of NPPV for treatment of respiratory failure for patients experiencing an acute exacerbation of COPD14; and lastly the use of nocturnal NPPV for treatment of COPD patients.15
NPPV for weaning intubated patients: Burns et al.11 Pooling of results from eight studies that included only patients with COPD provided strong evidence that NPPV weaning reduced mortality of intubated adults compared with invasive weaning (RR 0.42, 95% CI 0.25, 0.69). Ten trials with a total of 485 patients (seven exclusively COPD; 344 participants, three mixed population; 141 participants) showed a significant benefit for the use of NPPV weaning compared with invasive positive pressure ventilation (IPPV) for ICU LOS (weighted mean difference (WMD) −6.27, 95% CI −8.77, −3.78). There was also a significant benefit for hospital LOS (WMD −7.19, 95% CI −10.80, −3.38) observed when data from eight studies with a total of 401 patients (five exclusively COPD; 260 participants, three mixed populations; 141 participants).
NPPV for respiratory failure during exacerbations of COPD: Ram et al14 Ten studies (622 participants) reported on mortality and found a significant decrease in mortality with NPPV compared with standard care (RR 0.52, 95% CI 0.35, 0.76). Hospital LOS was reported in eight studies (546 patients) and found to be significantly shorter (WMD −3.24 days, 95% CI −4.42, −2.06 days) with NPPV, and although there was a trend towards shorted stay in the ICU, this was not found to be statistically significant. Data from five and four studies were used for meta-analysis of PaCO2 and PaO2 1 h following NPPV. PaCO2 improved (WMD −0.40 kPa, 95% CI −0.78, −0.03); however, PaO2 did not significantly increase.
Nocturnal NPPV for stable COPD: Wijkstra et al.15 There was no change in reported FEV1 or FVC between nocturnal NPPV and the control (four studies each, total of 67 participants). Although non-significant, metaanalysis of data from four studies and 67 participants showed small differences in PaO2 and PaCO2 that favoured NPPV. Exercise tolerance, measured by the 6 min walk test, was improved in two studies; however,
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this result was not significant. Sleep efficiency was found to be non-significantly decreased with NPPV when the data from three studies were combined.
Neuromuscular stimulation: Maddocks et al.12 Subgroup analysis for COPD patients was not performed; however, there were significant benefits to NMES found for both quadriceps muscle strength (standardised mean difference 0.90, 95% CI 0.33, 1.46; eight studies) and exercise performance demonstrated using three different tests; 6 min walk test (mean difference (MD) 40.05 m, 95% CI −4.14, 84.24 m; four studies), incremental shuttle walk test (MD 68.80 m, 95% CI 18.54, 119.06 m; one study) and endurance shuttle walk test (SD 160.22 m, 95% CI 33.73, 286.70 m; two studies). Two studies found improvements in self-reported breathlessness following an NMES programme (data not given), and three studies indicated improvements in overall HRQoL for patients who received NMES (data not given).
PEP device airway clearance technique: Osadnik et al.13 Outcome data were separated for acute exacerbations of COPD and stable COPD. For patients suffering exacerbations of COPD, hospital LOS was significantly reduced in the one study using PEP techniques that assessed this outcome (MD −1.10, 95% CI −1.89, −0.31; 33 participants). Lung function outcomes (FEV1 and FEV1/FVC (%)) were not significantly improved with the use of PEP airway clearance techniques compared with when no airway clearance technique was used in one study of 27 participants. PEP techniques did not significantly affect PaO2 or PaCO2 according to one study of 26 participants. There was not a significant difference in mortality between PEP airway clearance techniques and no airway clearance techniques groups. For patients with stable COPD, there was no significant difference in the total number of days in hospital; however, there was a significant decrease in the number of respiratory hospital admissions with the use of PEP devices (OR 0.27, 95% CI 0.08, 0.95; one study, 50 participants). The results regarding pulmonary function were generally small and inconsistent. Immediate FEV1 was slightly improved by PEP compared with no airway clearance technique (MD 0.04, 95% CI 0.00, 0.07; 23 participants), and no improvement on short-term FEV1 (two studies, 118 participants). No differences in gas exchange were observed between experimental and © 2014 Wiley Publishing Asia Pty Ltd
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control groups (one study, 90 participants). One study of 15 participants assessed the effect of PEP devices compared with a sham intervention on HRQoL measured by the St George’s Respiratory Questionnaire. The results favoured the intervention (MD −6.10, 95% CI −8.93 to −3.27). The same study also measured breathlessness and found a significant improvement (MD −0.30, 95% CI −0.53, −0.07) according to self-reports from 23 participants. Benefits of PEP device therapy were also reported for both short-term and long-term exercise tolerance. Short-term exercise tolerance as measured by the 6 min walk test improved significantly (MD 12.93, 95% CI 5.98, 19.98; 2 studies, 38 participants), and long-term exercise as measured by 12 min walk test also improved according to one study (MD 111.00, 95% CI 66.46, 155.54). There were no data for mortality for patients with stable COPD using PEP devices.
DISCUSSION Summary of main results The included reviews all investigated the effectiveness in the treatment and management of device-based therapies used in the treatment and management of COPD. Five reviews covering NPPV, nocturnal NPPV, PEP devices and NMES were included in this overview. Data from high-quality RCTs indicate that NPPV might be used in addition to standard care in the treatment of patients with acute respiratory failure due to exacerbations of COPD. Results show that NPPV decreased mortality and hospital LOS and improved respiratory rate. NPPV could also be beneficial as a weaning strategy for intubated patients with respiratory failure, with results from clinical trials showing significant reductions in mortality and hospital and ICU LOS. No study reported on QoL outcomes, and further evidence from larger samples sizes is needed before this strategy can be recommended for use in this patient group. Nocturnal NPPV for 3 months did not show significant effects on pulmonary function, gas exchange or exercise capacity. Though non-significant, there was a trend towards decreased sleep efficiency. Overall, the data do not support the use of nocturnal NPPV for the treatment of individuals with COPD at present; however, the small overall sample size precluded a definitive conclusion. Evidence regarding the use of PEP airway clearance techniques did not support their use in the treatment of patients with COPD. PEP techniques were deemed to be safe, but did not significantly or clinically benefit patients © 2014 Wiley Publishing Asia Pty Ltd
according to majority of the outcome measures reported on. There were some benefits seen for patients with stable COPD related to reduced hospital admissions, improved exercise ability and improvements in self-reported breathlessness and QoL; however, most of these data came from single studies with small sample sizes. NMES programmes were found to be effective for patients with COPD in managing muscle weakness and improving exercise tolerance, though the latter result only showed a moderate improvement that has questionable clinical significance. Symptoms of breathlessness (self-reported) were also found to be improved, and overall HRQoL was found to improve in three studies. Moreover, NMES was found to be a safe intervention and particularly suitable for those patients who were unable to participate in traditional exercise programmes.
Overall completeness and applicability of the evidence This overview aimed to determine the effectiveness of device and mechanical interventions used in the treatment and management of COPD, exacerbations of COPD and respiratory failure due to COPD. The review includes completed and recently updated Cochrane reviews, and the evidence report is therefore considered to be up to date and current. The included systematic reviews all involved participants with COPD, and where populations were mixed, only data pertaining to patients with COPD were extracted. Due to the heterogeneity of the participants and interventions between the systematic reviews, it was not possible to directly or indirectly compare the effects of the different interventions.
AUTHORS’ CONCLUSIONS Implications for practice Overall, the implications for practice based on the evidence presented for each intervention are the following: PEP device airway clearance techniques are safe but of limited clinical value. Such devices might have greater benefit for patients with acute exacerbations of COPD, but there is no clear evidence for benefits of this strategy for individuals with stable COPD. NMES regimens are safe and effective interventions for combating muscle weakness in patients with COPD, and might provide a benefit for exercise tolerance, symptoms of breathlessness and quality of life. NMES could be of particular benefit for patients who are unable to participate or maintain other forms of exercise.
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Chronic obstructive disease interventions
• There is no evidence to recommend the use of noctur•
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nal NPPV for patients with stable COPD; however, the evidence base for this intervention was limited by the small overall sample size. NPPV appears to be a preferable weaning strategy compared with IPPV for intubated patients with respiratory failure; however, the evidence is currently not sufficient to warrant formal recommendations for use of this strategy in practice. Data suggest that NPPV might be recommended as an adjunct therapy to usual medical care for management of patients with respiratory failure due to an acute exacerbation of COPD, where appropriate; however, further studies regarding selection of patients suitable for this strategy are needed.
Implications for research Further research is needed surrounding the use of all interventions covered in this overview, and is particularly warranted given the significant social and economic burdens of COPD worldwide. In particular: Additional RCTs are needed for the assessment of nocturnal NPPV as the existing evidence base is too small to draw meaningful conclusions from. Future studies on PEP airway clearance techniques would be strengthened if there was consistency in outcome measures used in studies, as many outcomes were informed by only one study. Although the evidence regarding NPPV as a weaning strategy for intubated patients is encouraging, a welldesigned and adequately powered RCT is needed to directly investigate the effectiveness of this strategy compared with other approaches to weaning. Any future work surrounding NMES for COPD patients should focus on defining optimal parameters for treatment programmes, identification of patients most likely to benefit from NMES programmes, and should include other outcome measures such as mortality and hospitalization events. Similarly, more data are needed regarding patients with acute exacerbations of COPD and respiratory failure that would be suitable for NPPV treatment. The feasibility, safety and effectiveness of this approach need to be explored in different settings, and the use of NPPV as an alternative to intubation for patients with respiratory failure should also be investigated.
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CONFLICT OF INTEREST None to declare.
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disease. Cochrane Database of Systematic Reviews 2012; (3): CD008328. 14 Ram FS, Picot J, Lightowler J, Wedzicha JA. Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews 2004; (3): CD004104. 15 Wijkstra PJ, Lacasse Y, Guyatt GH, Goldstein RS. Nocturnal non-invasive positive pressure ventilation for stable chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews 2002; (3): CD002878.
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SUPPORTING INFORMATION Additional Supporting Information may be found in the online version of this article at the publisher’s web-site: Appendix Appendix Appendix Appendix reviews.
SI Critical appraisal instrument. SII Data extraction instrument. SIII Characteristics of included reviews. SIV Summary of evidence from included
