Instruments for assessing the quality of drug studies published in the medical literature.
OBJECTIVE
To develop valid and reliable instruments to assess the methodologic quality and clinical relevance of drug studies.


METHODS
We developed an instrument to assess the methodologic quality of articles reporting clinical research and an instrument to measure nonmethodologic measures of quality, such as clinical relevance, generalizability, and adherence to ethical standards. Each instrument was pretested by seven independent, masked reviewers and modified based on interrater agreement and content validity of individual items. We determined correlational validity of the final methodologic quality instrument by comparing quality scores assigned to 10 articles by means of our instrument and a previously published one.


METHODS
Clinical drug studies published in symposium proceedings and peer reviewed biomedical literature.


METHODS
Interrater reliability of overall quality scores, measured by intraclass correlation (r) and Kendall's coefficient of concordance (W), and interrater reliability of individual items, by percentage agreement.


RESULTS
The interrater reliability of the pretest methodologic quality instrument was high (r = .89 [95% confidence interval, .73 to .96]; W = 0.64). Correlational validity of the final instrument was suggested by the high degree of concordance with another previously published one (W = 0.74). The interrater reliability of the pretest clinical relevance instrument was moderate (r = .41 [95% confidence interval, .18 to .64]; W = 0.47). Reviewers confirmed the content validity of both instruments.


CONCLUSIONS
The two instruments we developed, one measuring methodologic quality and one measuring clinical relevance of articles reporting clinical research, are reliable, valid, and applicable to a variety of research designs.
Institute for Health Policy Studies, School of Medicine, University of California-San Francisco 94109.
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D004341:Drug Evaluation; D017712:Peer Review, Research / Q000379:methods; D011643:Publishing / Q000592:standards; D011786:Quality Control; D015203:Reproducibility of Results