Table H4aAssociation between improvement in glycemic control and number of quality improvement strategies stratified by study sample size, but with number of QI strategies including important substrategies

Median Reduction in HbA1c
[inter-quartile range]
N=Number of trials
Number of QI Strategies *All TrialsTrials with sample size in lowest quartileTrials with sample size in lower 2 quartilesTrials with sample size in upper 2 quartilesTrials with sample size in highest quartile
Any number of strategies 0.481.350.800.210.10
[0.20, 1.38][0.60,1.48][0.41, 1.44][0.10, 0.60][0.10, 0.33]
N=38N=10N=19N=19N=10
1 strategy only 0.00-0.20 ^0.150.000.00
[0.0,0.10]——[0.10,0.20][0.00,0.11][0.00,0.00]
N=5N=1N=2§N=3N=2
≥ 2 strategies 0.601.401.080.340.15
[0.30, 1.40][0.71,1.50][0.47, 1.47][0.10, 0.73][0.10, 0.40]
N= 33N=9N=17N=16N=8
≥ 3 strategies 0.661.351.190.550.35
[0.33, 1. 40][1.15, 1.40][0.53, 1.40][0.20, 1.18][0.17, 0.53]
N=22N=4N=10N=12N=4
≥ 4 strategies 0.60.710.590.60.50
[0.41,1.1]——[0.43,0.99][0.4, 1.5][0.35,0.55]
N=13N=1N=6N=7N=3
≥ 5 strategies 0.710.710.710.850.40
[0.53,1.29]——[0.59,1.09][0.50,1.53][0.20,0.60]
N=7N=1N=3N=4N=2
6 strategies* 1.090.711.09
[0.71,1.47]——[0.71,1.47]
N=2N=1N=2N=0N=0
*

Under this alternate classification of the QI strategies, Five studies were still single-faceted, 15 but the median number of strategies increased from two to three and the maximum number of strategies increased from five to six (seen in two comparisons 6, 7).

^

All changes were standardized to reflect reductions. Thus, the negative sign here indicates an increase in serum HbA1c

When N=2, the numbers in square brackets reflect the results for each of the two studies rather than the inter-quartile range.

From: Appendix H, Additional tables for diabetes results and analysis

Cover of Closing the Quality Gap: A Critical Analysis of Quality Improvement Strategies (Vol. 2: Diabetes Care)
Closing the Quality Gap: A Critical Analysis of Quality Improvement Strategies (Vol. 2: Diabetes Care).
Technical Reviews, No. 9.2.
Shojania KG, Ranji SR, Shaw LK, et al.

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