Table 3Association of study design and patient outcomes

Study DesignNumber of StudiesReported improvements in clinical statusReported improvements in guideline adherenceReported improvements in functional statusReported improvements in health services utilization
Controlled before-after trial3215 (47%)16 (50%)2 (6%)8(25%)
RCT13444 (33%)32 (24%)19 (14%)23 (17%)
Quasi-RCT54 (80%)1 (20%)1 (20%)4 (80%)
p value*-0.040.0120.40.002
*

Chi squared test of study design × improvement in each type of outcome. We note that not all of the studies were designed to evaluate all types of outcomes.

From: 3, Results

Cover of Closing the Quality Gap: A Critical Analysis of Quality Improvement Strategies (Vol. 5: Asthma Care)
Closing the Quality Gap: A Critical Analysis of Quality Improvement Strategies (Vol. 5: Asthma Care).
Technical Reviews, No. 9.5.
Bravata DM, Sundaram V, Lewis R, et al.

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