Background
What is a pragmatic strategy?
Database | Description of contents |
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The Census data | Contains the sociodemographic profile and a measure of deprivation associated with different regions (small regions called dissemination areas). |
The Client Agency Enrolment Program | Tracks patient enrollment to individual family physicians. |
The Corporate Provider Database | Captures physician demographic and training information, and tracks their enrolment in practices and the primary care service organizations. |
The Discharge Abstract Database | Provides information on all acute care hospitalizations. |
The National Ambulatory Care Reporting System (NACRS) | Provides information on all emergency department encounters and same day surgeries. |
The Ontario Drug Benefit Program Database | Tracks all provincially reimbursed prescription drug products dispensed to Ontarians aged 65 years and older or receiving social assistance. |
The Ontario Health Insurance Plan Claims History Database | Captures information regarding in-and-out patient physician services and outpatient diagnostic and laboratory services. |
The Ontario Physician Human Resources Database | Identifies area of specializations for physicians and allows primary care providers who are generalists to be identified. |
The Registered Person’s Database | Captures demographic information and vital status (alive/deceased) for all Ontarians insured under the Ontario Health Insurance Plan |
The Statistics Canada’s Postal Code Conversion File | Allows patients to be attributed to a census dissemination area based on postal code. |
Main text
Confusions and controversies about pragmatic trials and how to deal with them
Ethics
Addressing the criticisms: the CHAP trial
• P: Among midsized Ontario communities, |
• I: does a highly organized, community-based program that combines offering blood pressure assessments and recording of CVD risks to everybody > 65 years old with peer health volunteer-delivered education and referral of all new or uncontrolled hypertensives to a source of continuing care (CHAP session), |
• C: compared with usual care (that is, absence of this community-based program), |
• O: reduce community rates of hospitalization for acute myocardial infarction, stroke and congestive heart failure |
• T: over 12 months? |
How pragmatic was the CHAP trial?
How did we address the key criticisms about pragmatic trials in the CHAP trial?
Criticism 1: High rate of loss to follow-up
Criticism 2: Non-adherence to study intervention
Criticism 3: Unblinded patients and physicians and patient self-assessments
Topic | Resource |
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The what, how, and why | 1 Sackett DL. Clinician-trialist rounds: 16. Mind your explanatory and pragmatic attitudes! - part 1: what? Clin Trials. 2013; 10(3):495–8. |
2 Macpherson H. Pragmatic clinical trials. Complement Ther Med. 2004 Jun-Sep; 12(2–3):136–40. | |
3 Sackett DL. Clinician-trialist rounds: 17. Mind your explanatory and pragmatic attitudes! Part 2: How? Clin Trials. 2013 Aug; 10(4):633–6. | |
4 Staa TP, Goldacre B, Gulliford M, Cassell J, Pirmohamed M, Taweel A, et al. Pragmatic randomised trials using routine electronic health records: putting them to the test. BMJ. 2012; 344:e55. | |
5 McMahon AD. Study control, violators, inclusion criteria and defining explanatory and pragmatic trials. Stat Med. 2002 May 30; 21(10):1365–76. | |
6 Tunis SR, Stryer DB, Clancy CM. Practical clinical trials: increasing the value of clinical research for decision making in clinical and health policy. JAMA. 2003 Sep 24; 290(12):1624–32. | |
7 Yoong SL, Wolfenden L, Clinton-McHarg T, Waters E, Pettman TL, Steele E, Wiggers J: Exploring the pragmatic and explanatory study design on outcomes of systematic reviews of public health interventions: a case study on obesity prevention trials. J Public Health (Oxf) 2014, 36(1):170–176. | |
Ethical issues pragmatic trials using cluster randomization | 8 Hutton JL. Are distinctive ethical principles required for cluster randomized controlled trials? Stat Med. 2001 Feb 15; 20(3):473–88. |
9 McRae AD, Weijer C, Binik A, Grimshaw JM, Boruch R, Brehaut JC, et al. When is informed consent required in cluster randomized trials in health research? Trials. 2011; 12:202. | |
10 Chaudhry SH, Brehaut JC, Grimshaw JM, Weijer C, Boruch R, Donner A, et al. Challenges in the research ethics review of cluster randomized trials: international survey of investigators. Clin Trials. 2013 Apr; 10(2):257–68. | |
PRECIS (pragmatic-explanatory continuum indicator summary) design tool and applications | 11 Riddle DL, Johnson RE, Jensen MP, Keefe FJ, Kroenke K, Bair MJ, et al. The Pragmatic-Explanatory Continuum Indicator Summary (PRECIS) instrument was useful for refining a randomized trial design: experiences from an investigative team. J Clin Epidemiol. 2010 Nov; 63(11):1271–5. |
12 Thorpe KE, Zwarenstein M, Oxman AD, Treweek S, Furberg CD, Altman DG, et al. A pragmatic-explanatory continuum indicator summary (PRECIS): a tool to help trial designers. J Clin Epidemiol. 2009 May; 62(5):464–75. | |
13 Zwarenstein M, Treweek S. What kind of randomized trials do we need? J Clin Epidemiol. 2009 May; 62(5):461–3. | |
14 Maclure M. Explaining pragmatic trials to pragmatic policymakers. J Clin Epidemiol. 2009 May; 62(5):476–8. | |
15 Tosh G, Soares-Weiser K, Adams CE. Pragmatic vs explanatory trials: the pragmascope tool to help measure differences in protocols of mental health | |
16 Randomized controlled trials. Dialogues in clinical neuroscience. 2011; 13(2):209–15. | |
17 Koppenaal T, Linmans J, Knottnerus JA, Spigt M. Pragmatic vs. explanatory: an adaptation of the PRECIS tool helps to judge the applicability of systematic reviews for daily practice. J Clin Epidemiol. 2011 Oct; 64(10):1095–101. | |
18 Selby P, Brosky G, Oh PI, Raymond V, Ranger S. How pragmatic or explanatory is the randomized, controlled trial? The application and enhancement of the PRECIS tool to the evaluation of a smoking cessation trial. BMC Med Res Methodol. 2012; 12:101. | |
Reporting of pragmatic trials | 19 Zwarenstein M, Treweek S, Gagnier JJ, Altman DG, Tunis S, Haynes B, et al. Improving the reporting of pragmatic trials: an extension of the CONSORT statement. BMJ. 2008; 337:a2390. |
20 Campbell MK, Piaggio G, Elbourne DR, Altman DG. Consort 2010 statement: extension to cluster randomised trials. BMJ. 2012; 345:e5661. | |
21 Hopewell S, Clarke M, Moher D, Wager E, Middleton P, Altman DG, et al. CONSORT for reporting randomised trials in journal and conference abstracts. Lancet. 2008 Jan 26; 371(9609):281–3. |
Criticism 4: Less perfect experiments than efficacy trials
Criticism 5: Compromising internal validity to achieve generalizability
Criticism 6: Large sample size requirements for small treatment effects
Conclusions
“If a 320 km/hr Ferrari Spider works well on an Formula-1 circuit, but crawls along the M-25 (major highway in the UK) during the morning and evening traffic jams:
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• an explanatory trialist would lament that testing the Ferrari on the M25 “lacks internal validity”
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• a pragmatic trialist would conclude that the “Ferrari is a waste of money for a daily commute!”
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