Doctors’ versus patients’ global assessments of treatment effectiveness: empirical survey of diverse treatments in clinical trials
BMJ 2008; 336 doi: https://doi.org/10.1136/bmj.39560.759572.BE (Published 05 June 2008) Cite this as: BMJ 2008;336:1287
- Evangelos Evangelou, research associate1,
- Georgios Tsianos, research associate1,
- John P A Ioannidis, professor1
- 1Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
- Correspondence to: J P A Ioannidis jioannid{at}cc.uoi.gr
- Accepted 7 April 2008
Abstract
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; I2=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; I2=0%, 0% to 24%).
Conclusion Doctors’ global assessments of the effects of treatments are on average similar to those of patients.
Footnotes
We thank Peter Tugwell and Theodore Pincus for useful comments on the manuscript.
Contributors: JPAI had the original idea for this project and proposed the design. All authors worked on the protocol. EE and GT extracted the data and JPAI oversaw the collected data and arbitrated on discrepancies. EE did the statistical analysis with help from JPAI. All authors interpreted the data. JPAI and EE wrote the manuscript and all authors revised drafts and approved the final version. JPAI is guarantor.
Competing interests: None declared.
Ethical approval: Not required.
Provenance and peer review: Not commissioned; externally peer reviewed.