Doctors' versus patients' global assessments of treatment effectiveness: empirical survey of diverse treatments in clinical trials.

Objective: To examine whether doctors' global assessments of treatment effects agree with patients' global assessments.

Design: Survey of trials included in systematic reviews of treatments for diverse conditions.

Data Sources: Cochrane database of systematic reviews. Data extracted Data on patients' global assessments and on doctors' global assessment for the same treatment against the same comparator.

Main Outcome Measures: Relative odds ratio (ratio of odds ratios of global improvement with the experimental intervention versus control according to doctors compared with patients), and improvement rates according to doctors and patients.

Results: Doctors' global assessments were compared with patients' global assessments for 63 different treatment comparisons (240 trials) in 18 conditions. The summary relative odds ratio across the comparisons was not significant (0.98, 95% confidence interval 0.88 to 1.08; I(2)=0%, 95% confidence interval 0% to 30%). In 62 of the 63 comparisons the effects of treatment rated by patients and by doctors did not differ beyond chance, but for single comparisons the confidence intervals were large. Rates of improvement on average did not differ between doctors' assessments and patients' assessments (summary relative odds ratio 0.98, 0.88 to 1.06; I(2)=0%, 0% to 24%).

Conclusion: Doctors' global assessments of the effects of treatments are on average similar to those of patients.