You are here

  • Home
  • Archive
  • Volume 9, Issue 1
  • Psychosocial factors associated with coping behaviour after inpatient treatment for substance use disorder: a systematic review study protocol

Article Text

Article menu

Download PDFPDF

XML
Addiction
Protocol
Psychosocial factors associated with coping behaviour after inpatient treatment for substance use disorder: a systematic review study protocol
  1. Dagny Adriaenssen Johannessen1,2,
  2. Trond Nordfjærn3,
  3. Amy Østertun Geirdal2
  1. 1 Blue Cross East, Oslo, Norway
  2. 2 Department of Social Work, Child Welfare and Social Policy, OsloMet – Oslo Metropolitan University, Oslo, Norway
  3. 3 Department of Psychology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
  1. Correspondence to Dagny Adriaenssen Johannessen; dagnjo{at}oslomet.no

Abstract

Introduction Much is known about factors associated with coping with abstinence from substance use. The planned systematic review aims to summarise available studies exploring the change in psychosocial factors associated with coping after long-term (≥3 months) inpatient treatment for substance use disorder (SUD). Examples of psychosocial factors of interest are social support, housing, activity (eg, employment and education) mental health and quality of life. Coping behaviour can be understood as responses or actions taken in a stressful situation, particularly how psychosocial factors affect a person’s coping behaviour with abstinence from substances in everyday life (characterised as a stressful situation).

Methods and analysis A set of text words were developed based on the population (people with SUD), exposure (long-term inpatient SUD treatment), outcome (psychosocial factors) and study design (prospective cohort studies) of interest. A systematic search will be conducted in eight electronic databases: Campbell Collaboration Library, Cochrane Library, EMBASE, Epistemonikos, Medline, PsychINFO, Social Sciences Citation Index and SocINDEX. The titles and abstracts will be screened for relevance before a pre-piloted data collection form will be used to evaluate eligibility and extract data from the search results. The planned review will include peer-reviewed study reports published in English or Scandinavian language.

Ethics and dissemination The target group, people with SUD, might be considered as vulnerable. Based on this, the population will be the group of interest in the planned systematic review of studies that have already been conducted. Patients and the general public will not be involved in the development of this systematic review. The results will be summarised in a study report and submitted to a peer-reviewed international journal. Additionally, results will be disseminated in the mass media and at international research conferences.

PROSPERO registration number CRD42018087408.

  • substance use disorder
  • treatment outcome
  • psychosocial factors
  • followup studies
  • systematic review

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.

https://doi.org/10.1136/bmjopen-2018-022673

Statistics from Altmetric.com

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    Strengths and limitations of this study

    • Prioritisation of resources entailed that this review will be restricted to contain study reports published in English or Scandinavian languages only.

    • In the current review, the systematic search will only be conducted in databases containing published reports, not databases including unpublished or ongoing studies.

    • One author will conduct the first selection steps, which is considered as a limitation due to the risk of potential selection bias in the selection process. However, two authors will evaluate the studies marked as clear and unclear in the first screening. If there is disagreement, then the third author will read and decide the eligibility of the study in question.

    • The number of searched databases facilitates reaching a broad range of published study reports.

    • To our knowledge, there are no former systematic reviews of psychosocial factors associated with coping behaviour after long-term inpatient substance use disorder treatment.

    Introduction 

    Much is known about factors associated with coping with abstinence from substance abuse. Examples of such factors are social support and appropriate housing conditions,1–7 meaningful activity (eg, employment or education),1–4 6 8 9 treatment completion and commitment to continued care discharge plans.3 8 10 In the 10th edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10), substance use disorder (SUD) is described as ‘A cluster of physiological, behavioural, and cognitive phenomena in which the use of a substance or a class of substances takes on a much higher priority for a given individual than other behaviours that once had greater value’ (p. 75).11

    Substantial resources are used internationally to provide SUD treatment, substitution treatment and treatment of SUD-related health problems.12 SUD treatment can be described as interventions and measures aiming to alter conditions leading to destructive behaviour and corroborate behaviour that reduces problematic substance use, and that takes place at a treatment facility where the patient is a resident.13 Even though it is estimated that >50% relapse to substance use after completed SUD treatment9 14 15 and between 17% and 57% patients drop out from SUD treatment before planned discharge,16 inpatient SUD treatment is considered as a factor which may promote sustained abstinence.17

    Due to the considerable resources used to provide SUD treatment and because people with SUD often strive with multiple psychosocial challenges and comorbidity,18 19 the planned review will be narrowed to contain inpatient SUD treatment with a duration of ≥3 months. The reason for excluding studies exploring treatment with a duration of <3 months is that previous research has shown an association between patient outcome and treatment with a duration of >3 months.20 21 Hereafter, long-term treatment refers to a treatment duration of ≥3 months. The reason to focus exclusively on inpatient treatment is to reach studies with a SUD population that strives to handle their everyday life (eg, attending appointments, living at home, attending work or activities and maintaining daily routines). Additionally, previous systematic reviews and meta-analysis have summarised effect-studies of various outpatient services.22–25

    In the planned review, psychosocial factors refer to change related to social support, housing, activity (eg, employment and education), mental health and quality of life after completed inpatient SUD treatment. Coping can be understood as responses or actions taken in a stressful situation, or coping behaviour.26 In the context of the planned review, it is of interest to examine how psychosocial factors affect a person’s coping behaviour with abstinence from substances in everyday life. Everyday life as abstinent after SUD treatment may be characterised as a stressful situation.

    The target group of this review, people with SUD, might be considered as a vulnerable group. On this background, this target group will be the population of interest in an effort to gather, unify and summarise available studies about psychosocial factors associated with coping after long-term inpatient SUD treatment.

    The primary aim of this review is to explore how psychosocial factors are associated with coping after inpatient SUD treatment. To our knowledge, no systematic reviews with a similar aim have been conducted previously. The planned systematic review aims to explore the following:

    What psychosocial factors are associated with coping after inpatient treatment for substance use disorder?

    Methods and analysis

    The planned systematic review will include studies that meet the eligibility criteria presented in the upcoming section.

    The presented objectives are systematised according to the PECO (population, exposure, comparison, outcome)27 presented in table 1.

    View this table:
    Table 1

    PECO

    The PECO lays ground for the selected text words and facilitates the limitation criteria of the population, treatment setting and outcome of interest.

    Inclusion criteria

    The search will be conducted in relevant electronic databases, which are outlined below, containing peer-reviewed study reports. The determined inclusion criteria, which will be presented in the following section, are deliberately made fairly narrow to broaden the probability to find studies that can highlight the current issue.

    Participants

    The population of interest are adult (≥18 years) people with SUD. In the current review, SUD is defined as outlined in the introduction. However, in the planned systematic search people who are admitted to inpatient SUD treatment are also characterised as struggling with SUD. Therefore, both studies which include a diagnostic measure of SUD and those which do not will be evaluated for eligibility.

    Treatment setting (exposure)

    The treatment setting of interest is inpatient SUD treatment with a duration of ≥3 months.

    Comparison

    All studies that explore long-term SUD treatment will be evaluated for eligibility regardless if they are compared with modalities that are considered as non-eligible in the planned systematic review.

    Outcomes

    The outcomes of interest are change in psychosocial factors (eg, housing, employment, mental health or quality of life) related to coping after completed inpatient SUD treatment. Because a multitude of measurement instruments often are used to measure overlapping/similar constructs and to broaden the probability of reaching studies that examine various types of psychosocial outcomes, there were no eligibility criteria in terms of how the outcome was measured.

    Measures revealing the prevalence of continued substance use after discharge from inpatient SUD treatment are considered as secondary outcomes of interest.

    Type of study

    This review will consider all available eligible prospective cohort studies with one or more measurement point(s) after discharge from inpatient SUD treatment.

    Search strategy

    The search string used in the main search (see the online supplementary appendix 1) and the text words (see the online supplementary appendix 2) is determined using the PECO model. Relevant subject headings (see the online supplementary appendix 3) have been identified in each of the included databases. A set of text words for this particular systematic search has been designed by exploring the definitions, keywords and indexing of articles with a similar topic and aim as the planned review. Together, the combination of the text words and the subject headings constitute the search string used in each of the included databases.

    Supplementary file 1

    Supplementary file 2

    Supplementary file 3

    To decide if the search should be restricted to a particular timespan, a search for systematic reviews was conducted in Campbell Collaboration, Cochrane Library and Epistemonikos (see the online supplementary appendix 4). The search yielded one relevant systematic review published in 2014, exploring the effectiveness of one specific SUD treatment approach. The aims of the mentioned review were narrower than the one of this planned review and we will, therefore, avoid timespan restrictions in the systematic search. We will include all studies written in English or Scandinavian languages, published before the time of the systematic search.

    Supplementary file 4

    To increase the probability of finding studies which are not embraced by the chosen databases, a citation search of included studies will be conducted. Additionally, the 100 first hits from an advanced search in Google Scholar will be screened for eligible studies (reported as other sources). The selection of databases is done based on advice from academic librarians and experienced researchers with expertise on the field. Guidelines collected from relevant literature sources, such as the Cochrane handbook for systematic reviews of interventions,28 are also used in the decision of which databases to include. The aim of this review is at an intersection point between medicine/health and social sciences. Therefore, we have selected databases with its main focus in these sciences. A comprehensive search will be conducted in the following databases: Campbell Collaboration Library, Cochrane Library, EMBASE, Epistemonikos, Medline, PsychINFO, Social Sciences Citation Index and SocINDEX.

    Data

    Data selection

    The results from the systematic search will be combined and controlled for duplicates using EndNote X8. The remaining search results will further be evaluated through two selection steps. The titles and abstracts will be screened for relevance by one author (DAJ), using EndNote X8. In the first selection step, obviously irrelevant studies will be eliminated. In the second selection step, remaining studies will be evaluated using a data selection form developed by the authors. The data selection form will be piloted on a sample of 100 studies. The remaining studies will initially be screened for eligibility by one author (DAJ), and identified as include, exclude or unclear, and then be screened by the second author (TN) with a specific focus on which are unclear. Diverse evaluation of eligibility should be resolved by discussion. In case of disagreement, the third author (AØG) will decide the eligibility of the study in question.

    To demonstrate the selection steps taken in the process of data selection, a Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) Flow Diagram will be included in the review. The listed inclusion criteria in the data selection form are arranged in the same order as the reason for exclusion will be reported (excluded in the order: (1) participants, (2) setting, (3) study design and (4) outcome). Meaning that a study that does not meet the inclusion criteria based on the included participants will be reported as excluded on the background of participants, even if the study also may be excluded based on the setting or study design.

    Data extraction

    A predetermined data extraction form will be used, deciding which data to extract from the included study reports. The form is developed by the authors, based on the aim and inclusion criteria. The data extraction form will be piloted on a sample of 10 studies.29 The quality of the included study will be appraised by using the Critical Appraisal Skills Programme (CASP)30 checklist tool developed to evaluate the relevance of the included cohort studies. The evaluation and data extraction of the final studies will be done by one author (DAJ).

    In case of missing data or disagreement regarding the extracted data, the corresponding author of the study in question will be contacted to address their opinion. If the corresponding author does not reply within 14 days, then the third author (AØG) will determine the eligibility of the study in question and the disagreement will be addressed in the review.

    Patient and public involvement

    Patients and/or the general public were not involved in the development of this systematic review. The results from the planned systematic review will be summarised in an article and submitted to an academic journal. Additionally, results will be disseminated in the mass media and at international research conferences.

    Critical appraisal

    Developing this protocol is an important initiative to counter selection and reporting bias. By developing transparent and clear-cut predetermined procedures before the screening of the results from the systematic search is undertaken, and by revealing the protocol with the published material, the risk of selection and reporting bias will be reduced.31

    We have adhered to the PRISMA for Protocol (PRISMA-P) in the development of this protocol (see the online supplementary appendix 5). The PRISMA-P consists of a checklist with 17 points used to ensure that the protocol facilitates a robust and transparent systematic review. Completing a PRISMA-P and making the protocol available minimises the risk of selective reporting, for instance, in the case of unexpected results.31 32

    Supplementary file 5

    To ensure a satisfying quality, the planned review will be reported according to the PRISMA before it is submitted to a journal.33 The PRISMA is a 27-items checklist used to evaluate the reporting in systematic reviews and meta-analyses. The PRISMA will also be used to evaluate reporting in potential reviews among the included studies.34

    There are three important aspects to appraise in the included study reports; method, study design and relevance in relation to the aim of the planned systematic review. The appraisal should be done before the studies are included in the systematic review.33 To facilitate such an appraisal and reduce the risk of bias, the CASP checklist will be used to evaluate the relevance and quality of the included cohort studies. CASP consists of 12 questions evaluating the study design, risk of bias, relevance and whether the results are useful to the current review.30

    Synthesis and analysis

    The approach of the planned synthesis will be a thematic summary. The presentation of the findings will be structured based on the characteristics of the extracted data. The findings will partly be reported through text summaries and partly through infographics presenting patient and study characteristics, patient outcome and prevalence of continued substance use after inpatient SUD treatment.

    In addition to psychosocial factors and continued substance use, the potential influence of demographic variables on the ability to cope without substance use after inpatient SUD treatment will be taken into consideration in the planned review.

    A meta-analysis will only be conducted if diversity in the preformed statistical analysis and if variety in characteristics of the included studies is not a concern, and if the effect sizes, mean and/or SD are reported consistently at baseline and follow-up in the finally included studies.

    Potential implications

    The planned systematic review may attain information about psychosocial factors that could serve as protective factors among patients after long-term SUD treatment. The results could provide knowledge about which psychosocial factors to be particularly aware of among patients undergoing long-term SUD treatment. These factors may, in turn, be addressed by targeted clinical initiatives. Additionally, the planned review may point out new avenues for further research on this topic.

    Ethics and dissemination

    The target group, people with SUD, might be considered as vulnerable. Based on this, the population will be the group of interest in the planned systematic review of studies that have already been conducted. Patients and the general public will not be involved in the development of this systematic review. The results will be summarised in a study report and submitted to a peer-reviewed international journal. Additionally, results will be disseminated in the mass media and at international research conferences. The planned systematic review has been registered at PROSPERO with registration ID: CRD42018087408.

    Review status

    At the time of submission, the systematic search has been conducted and the search results have been controlled for duplicates. The screening of titles and abstracts has started. The review is planned for submission in December 2018.

    References

    1. 1.↵
      2. Neale J ,
      3. Finch E ,
      4. Marsden J , et al
      . How should we measure addiction recovery? Analysis of service provider perspectives using online Delphi groups. Drugs 2014;21:310–23.doi:10.3109/09687637.2014.918089
      OpenUrl
    2. 2.↵
      2. Neale J ,
      3. Tompkins C ,
      4. Wheeler C , et al
      . "Youre all going to hate the word recovery by the end of this": Service users´ views of measuring addiction recovery. Drugs 2015;22:26–34.
      OpenUrl
    3. 3.↵
      2. Bergman BG ,
      3. Hoeppner BB ,
      4. Nelson LM , et al
      . The effects of continuing care on emerging adult outcomes following residential addiction treatment. Drug Alcohol Depend 2015;153:207–14.doi:10.1016/j.drugalcdep.2015.05.017
      OpenUrl
    4. 4.↵
      2. Manuel JI ,
      3. Yuan Y ,
      4. Herman DB , et al
      . Barriers and facilitators to successful transition from long-term residential substance abuse treatment. J Subst Abuse Treat 2017;74:16–22.doi:10.1016/j.jsat.2016.12.001
      OpenUrl
    5. 5.↵
      2. Spear SE ,
      3. Crevecoeur-MacPhail D ,
      4. Denering L , et al
      . Determinants of successful treatment outcomes among a sample of urban American Indians/Alaska Natives: the role of social environments. J Behav Health Serv Res 2013;40:330–41.doi:10.1007/s11414-013-9324-4
      OpenUrl
    6. 6.↵
      2. Von Greiff N ,
      3. Skogens L
      . Förändringsprocesser i samband med missbruksbehandling - vilka faktorer beskriver klienter som viktiga för att initiera och bibehålla positiva förändringar? Nordisk Alkohol- Og Narkotikatidsskrift 2012;29:195–209.
      OpenUrl
    7. 7.↵
      2. Pettersen H ,
      3. Landheim A ,
      4. Skeie I , et al
      . Why do those with long-term substance use disorders stop abusing substances? A qualitative study. Subst Abuse 2018;12:117822181775267.doi:10.1177/1178221817752678
      OpenUrl
    8. 8.↵
      2. Decker KP ,
      3. Peglow SL ,
      4. Samples CR , et al
      . Long-term outcomes after residential substance use treatment: Relapse, morbidity, and mortality. Mil Med 2017;182:e1589–e1595.doi:10.7205/MILMED-D-15-00560
      OpenUrl
    9. 9.↵
      2. Nordfjærn T
      . Relapse patterns among patients with substance use disorders. J Subst Use 2011;16:313–29.doi:10.3109/14659890903580482
      OpenUrl
    10. 10.↵
      2. Proctor SL ,
      3. Wainwright JL ,
      4. Herschman PL
      . Patient adherence to multi-component continuing care discharge plans. J Subst Abuse Treat 2017;80:52–8.doi:10.1016/j.jsat.2017.07.003
      OpenUrl
    11. 11.↵
      World Health Organization. ICD-10 Classification of Mental and Behavioural Disorders: Clinical Descriptions and Diagnostic Guidelines. Albany: World Health Organization, 1992.
    12. 12.↵
      European Monitoring Centre for Drugs and Drug Addiction. Drug treatment expenditure: a methodological overview. Lisbon, 2017.
    13. 13.↵
      2. Mørland J ,
      3. Waal H
      . Rus og avhengighet [Substances and addiction]. Oslo: Universitetsforl, 2016.
    14. 14.↵
      2. Blodgett JC ,
      3. Maisel NC ,
      4. Fuh IL , et al
      . How effective is continuing care for substance use disorders? A meta-analytic review. J Subst Abuse Treat 2014;46:87–97.doi:10.1016/j.jsat.2013.08.022
      OpenUrlCrossRefPubMed
    15. 15.↵
      2. Hunt WA ,
      3. Barnett LW ,
      4. Branch LG
      . Relapse rates in addiction programs. J Clin Psychol 1971;27:455–6.doi:10.1002/1097-4679(197110)27:4<455::AID-JCLP2270270412>3.0.CO;2-R
      OpenUrlCrossRefPubMedWeb of Science
    16. 16.↵
      2. Brorson HH ,
      3. Ajo Arnevik E ,
      4. Rand-Hendriksen K , et al
      . Drop-out from addiction treatment: a systematic review of risk factors. Clin Psychol Rev 2013;33:1010–24.doi:10.1016/j.cpr.2013.07.007
      OpenUrlCrossRefPubMed
    17. 17.↵
      2. Lauritzen G ,
      3. Nordfjærn T
      . Changes in opiate and stimulant use through 10 years: The role of contextual factors, mental health disorders and psychosocial factors in a prospective SUD treatment cohort study. PLoS One 2018;13:e0190381–16.doi:10.1371/journal.pone.0190381
      OpenUrl
    18. 18.↵
      2. Wakeman SE ,
      3. Metlay JP ,
      4. Chang Y , et al
      . Inpatient Addiction Consultation for Hospitalized Patients Increases Post-Discharge Abstinence and Reduces Addiction Severity. J Gen Intern Med 2017;32:909–16.doi:10.1007/s11606-017-4077-z
      OpenUrl
    19. 19.↵
      2. Wagner T ,
      3. Krampe H ,
      4. Stawicki S , et al
      . Substantial decrease of psychiatric comorbidity in chronic alcoholics upon integrated outpatient treatment - results of a prospective study. J Psychiatr Res 2004;38:619–35.doi:10.1016/j.jpsychires.2004.04.007
      OpenUrlCrossRefPubMedWeb of Science
    20. 20.↵
      2. Simpson DD ,
      3. Joe GW ,
      4. Fletcher BW , et al
      . A national evaluation of treatment outcomes for cocaine dependence. Arch Gen Psychiatry 1999;56:507–14.doi:10.1001/archpsyc.56.6.507
      OpenUrlCrossRefPubMedWeb of Science
    21. 21.↵
      2. Hubbard RL ,
      3. Craddock SG ,
      4. Anderson J
      . Overview of 5-year followup outcomes in the drug abuse treatment outcome studies (DATOS). J Subst Abuse Treat 2003;25:125–34.doi:10.1016/S0740-5472(03)00130-2
      OpenUrlCrossRefPubMedWeb of Science
    22. 22.↵
      2. Tanner-Smith EE ,
      3. Wilson SJ ,
      4. Lipsey MW
      . The comparative effectiveness of outpatient treatment for adolescent substance abuse: a meta-analysis. J Subst Abuse Treat 2013;44:145–58.doi:10.1016/j.jsat.2012.05.006
      OpenUrlCrossRefPubMed
    23. 23.↵
      2. McCarty D ,
      3. Braude L ,
      4. Lyman DR , et al
      . Substance Abuse Intensive Outpatient Programs: Assessing the Evidence. Psychiatric Services 2014;65:718–26.doi:10.1176/appi.ps.201300249
      OpenUrl
    24. 24.↵
      2. Penzenstadler L ,
      3. Machado A ,
      4. Thorens G , et al
      . Effect of Case Management Interventions for Patients with Substance Use Disorders: A Systematic Review. Front Psychiatry 2017;8.doi:10.3389/fpsyt.2017.00051
    25. 25.↵
      2. Watson JM ,
      3. Fayter D ,
      4. Mdege N , et al
      . Interventions for alcohol and drug problems in outpatient settings: a systematic review. Drug Alcohol Rev 2013;32:356–67.doi:10.1111/dar.12037
      OpenUrlCrossRefPubMedWeb of Science
    26. 26.↵
      2. Skinner EA ,
      3. Edge K ,
      4. Altman J , et al
      . Searching for the structure of coping: a review and critique of category systems for classifying ways of coping. Psychol Bull 2003;129:216–69.doi:10.1037/0033-2909.129.2.216
      OpenUrlCrossRefPubMedWeb of Science
    27. 27.↵
      2. O’Connor D ,
      3. Higgins JPT ,
      4. Green S
      . Defining the review question and developing criteria for including studies. In: Green S , Higgins JPT , eds. Cochrane handbook for systematic reviews of interventions: Version 5.1.0 (updated March 2011): The Cochrane Collaboration, 2011.
    28. 28.↵
      2. Lefebvre C ,
      3. Manheimer E ,
      4. Glanville J
      . Searching for studies. In: Green S , Higgins JPT , eds. Cochrane handbook for systematic reviews of interventions: Version 5.1.0 (updated March 2011: The Cochrane Collaboration, 2011.
    29. 29.↵
      2. Higgins JPT ,
      3. Deeks JJ
      . Selecting studies and collecting data. In: Green S , Higgins JPT , eds. Cochrane handbook for systematic reviews of interventions: Version 5.1.0 (updated March 2011): The Cochrane Collaboration, 2011.
    30. 30.↵
      Critical Appraisal Skills Programme. CASP Cohort Study Checklist. 2018 https://casp-uk.net/wp-content/uploads/2018/01/CASP-Cohort-Study-Checklist.pdf (Accessed 02 th July 2018).
    31. 31.↵
      2. Moher D ,
      3. Shamseer L ,
      4. Clarke M , et al
      . Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement. Syst Rev 2015;4:1.doi:10.1186/2046-4053-4-1
      OpenUrlCrossRefPubMed
    32. 32.↵
      2. Shamseer L ,
      3. Moher D ,
      4. Clarke M , et al
      . Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: Elaboration and explanation. 2015.
    33. 33.↵
      2. Gough DA ,
      3. Oliver S ,
      4. Thomas J
      . An introduction to systematic reviews. 2nd edition: SAGE, 2017.
    34. 34.↵
      2. Liberati A ,
      3. Altman DG ,
      4. Tetzlaff J , et al
      . The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. Ann Intern Med 2009;151:W65:W.doi:10.7326/0003-4819-151-4-200908180-00136
      OpenUrlCrossRefPubMedWeb of Science

    Footnotes

    • Patient consent for publication Not required.

    • Contributors DAJ, TN and AØG: contributed to the writing of this protocol.

    • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

    • Competing interests None declared.

    • Provenance and peer review Not commissioned; externally peer reviewed.