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. 2022 Sep 6;1(1):e000219. doi: 10.1136/bmjmed-2022-000219

Table 3.

Difference-in-difference estimates of adjusted change in value and number of industry payments per physician during the covid-19 pandemic (ie, January-February v April-December in 2020) compared with 2019 according to the type of payments

Type of payment Value of industry payments per physician (95% CI) No of industry payments per 100 physicians (95% CI)
Relative % change Absolute $ change Adjusted P value Relative % change Absolute change Adjusted P value
Total −48.4 (−50.6 to −46.2) −75.7 (−81.2 to −70.3) <0.001 −47.4 (−47.7 to −47.1) −43.6 (−44.2 to −43.0) <0.001
Meal −63.9 (−64.3 to −63.5) −14.9 (−15.1 to −14.7) <0.001 −46.0 (−46.3 to −45.7) −37.0 (−37.5 to −36.5) <0.001
Travel −93.8 (−94.3 to −93.3) −19.3 (−20.4 to −18.2) <0.001 −91.5 (−91.9 to −91.0) −5.9 (−6.1 to −5.7) <0.001
Consulting −15.7 (−23.5 to −6.9) −6.7 (−10.8 to −2.7) <0.001 6.6 (1.8 to 11.6) 0.1 (0.0 to 0.1) 0.01
Speaking fee −36.3 (−41.4 to −30.7) −13.1 (−15.7 to −10.5) <0.001 −34.4 (−36.8 to −31.8) −0.9 (−0.9 to −0.8) <0.001
Honorariums −48.5 (−55.9 to −39.9) −2.3 (−2.9 to −1.7) <0.001 7.9 (−28.8 to 63.5) 0.0 (−0.1 to 0.1) 0.72
Others −12.0 (−29.8 to 10.4) −1.1 (−2.8 to 0.6) 0.27 −25.7 (−28.7 to −22.6) −0.1 (−0.1 to 0.0) <0.001

Difference-in-difference estimates in relative percentage changes were calculated by regression coefficients of the interaction terms between the year indicator (ie, 2019 v 2020) and the month indicator (ie, January-February v April-December) in the multivariable negative binomial models adjusting for physicians’ gender, specialty, and practice location. The adjusted absolute changes in outcomes were estimated by calculating the differences in predicted outcomes at each level of the interaction terms for each observation and averaging over the entire sample. P value was adjusted for multiple comparisons using the Benjamini-Hochberg method.

CI=confidence interval.