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Comment and Response
July 8, 2013

Efficacy vs Effectiveness

Author Affiliations
  • 1Division of Preventive and Behavioral Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester
JAMA Intern Med. 2013;173(13):1262-1263. doi:10.1001/jamainternmed.2013.6521

To the Editor The recently published study by Ma et al1 (Evaluation of Lifestyle Interventions to Treat Elevated Cardiometabolic Risk in Primary Care [E-LITE] trial) tested 2 versions of the Diabetes Prevention Program (DPP) in the primary care setting and showed that both coach-based and DVD-based versions were superior to usual care. The investigators described their study as a “primary care-based translational intervention trial” and that these interventions have now been “proven effective in a primary care setting.”1(p113) We contend that the E-LITE study is an efficacy trial that has once again confirmed that the DPP works. That it works when DVD-delivered is promising because this is less intensive than a coach-based intervention. However, the trial actually offers little insight into adapting these interventions in a real-world primary care setting with real patients with metabolic syndrome. Effectiveness studies are designed to determine whether interventions, already proven efficacious under ideal circumstances, are effective when delivered in real-world settings, by staff in those settings, and with broad, representative populations.2 The E-LITE trial did not employ primary care staff to implement the interventions but instead used staff hired by the research team. Even the DVD-based intervention required staff to send reminders and field questions from participants. They also recruited a highly selective population by using 31 inclusion and exclusion criteria3 and randomizing only 15% of those screened by telephone. It remains unclear to what extent this sample represents typical patients with metabolic syndrome. The only real-world aspect of the study seems to be that the interventions were physically performed in the primary care clinic as opposed to a research laboratory. This lends very little insight into how to address the key challenges of conducting such interventions in the primary care setting, including identifying staff who can deliver the intervention, determining how staff time will be compensated, establishing whether primary care patients with medical and psychiatric comorbidities will participate and benefit, and determining how to feasibly incorporate the intervention into standard practice. Performing efficacy trials in clinical settings with study staff and highly selective study samples does not inform practice significantly more so than efficacy trials in laboratory settings that also use study staff and highly selective samples. To realize the potential of the efficacious lifestyle interventions, trials are needed that use real-world settings, employ staff in those settings, impose few exclusion criteria, and are designed to be integrated and delivered within the context of routine care by staff who could realistically and routinely deliver it.4

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