TABLE 3.

Trends, level changes, and physician‐level variations in fibrate prescribing before and after evidence

	Commercial	Medicare advantage
N	3 465 582	2 707 439
Inclusion of random effects P‐value	<.001	<.001
Pre‐evidence trend, β 50 (95% CI)	0.0012 (0.0010, 0.0014)	0.0017 (0.0013, 0.0020)
Pre‐evidence trend, σ 50	0.0161	0.0111
Pre‐evidence trend, CV	13.5386	6.7065
Pre‐evidence trend, Pseudo R 2	0.000	0.000
Pre‐evidence trend, β 51 Wald P‐value	.040	.268
Post‐evidence trend, β 50 + β 60 (95% CI)	−0.0016 (−0.0018, −0.0015)	−0.0005 (−0.0006, −0.0003)
Post‐evidence trend, σ 50 + σ60	0.0123	0.0102
Post‐evidence trend, CV	7.5351	22.6538
Post‐evidence trend, Pseudo R 2	0.000	0.000
Post‐evidence trend, β 51 + β 61 Wald P‐value	.013	.133
Change in trend, β 60 (95% CI)	−0.0028 (−0.0031, −0.0025)	−0.0021 (−0.0025, −0.0018)
Change in trend, σ 60	0.0236	0.0180
Change in trend, CV	8.3563	8.5451
Change in trend, Pseudo R 2	0.000	0.000
Change in trend, β 61 Wald P‐value	.390	.661
Change in level, β 40 (95% CI)	−0.0026 (−0.0049, −0.0004)	−0.0020 (−0.0050, 0.0009)
Change in level, σ 40	0.1650	0.1237
Change in level, CV40	62.6015	61.2152
Change in level, Pseudo R 2	0.000	0.000
Change in level, β 41 Wald P‐value	.480	.476

The pre‐evidence trend, post‐evidence trend, change in trend, and change in level are derived from ${\widehat{\beta }}_{50},{\widehat{\beta }}_{50}+{\widehat{\beta }}_{60},{\widehat{\beta }}_{60},$ and ${\widehat{\beta }}_{40}$ respectively in Equation 1. Standard deviations are derived from ${\widehat{\sigma }}_{50},\sqrt{{{\widehat{\sigma }}_{50}}^2+{{\widehat{\sigma }}_{60}}^2+2{\rho }_{56}{\widehat{\sigma }}_{50}{\widehat{\sigma }}_{60}},{\widehat{\sigma }}_{60},$and ${\widehat{\sigma }}_{40}$respectively in Equation 1. Pseudo R ² are derived by comparing standard deviations from Equation 1 to corresponding standard deviations in Equation 3. Wald tests assessed whether physician characteristic interactions in vectors ${\widehat{\beta }}_{51},{\widehat{\beta }}_{51}+{\widehat{\beta }}_{61},{\widehat{\beta }}_{61},$and ${\widehat{\beta }}_{41}$respectively in Equation 3 were jointly equal to zero.

Abbreviations: CI, confidence interval; CV, coefficient of variation.