| No. visits with a syndrome-positive physician claim | Bivariate regression analysis | Multivariate regression analysis1 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Encounter characteristics | Syndrome-positive in the chart (N = 2,967) | Syndrome-negative in the chart (N = 1,363) | Total (N = 4,330) | OR | 95% CI | P value | OR | 95% CI | P value | |||
 | No. | % | No. | % | No. | % |  |  |  |  |  |  |
Syndrome type: | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Fever | 371 | 12.5 | 230 | 16.9 | 601 | 13.9 | Ref. | Ref. | Ref. | Ref. | Ref. | Ref. |
   Gastrointestinal | 572 | 19.3 | 283 | 20.8 | 855 | 19.8 | 1.57 | (1.25, 1.97) | < 0.0001 | 1.72 | (1.36, 2.16) | < 0.0001 |
   Neurological | 608 | 20.5 | 363 | 26.6 | 971 | 22.4 | 1.29 | (1.05, 1.60) | 0.02 | 1.38 | (1.11, 1.72) | < 0.01 |
   Rash | 628 | 21.2 | 269 | 19.7 | 897 | 20.7 | 1.80 | (1.44, 2.25) | < 0.0001 | 1.89 | (1.51, 2.37) | < 0.0001 |
   Respiratory | 808 | 27.2 | 241 | 17.7 | 1049 | 24.2 | 1.72 | (1.36, 2.17) | < 0.0001 | 1.66 | (1.29, 2.14) | < 0.0001 |
   ILI | 555 | 18.7 | 98 | 7.2 | 653 | 15.1 | 2.98 | (2.32, 3.82) | < 0.0001 | 2.68 | (2.06, 3.48) | < 0.0001 |
Type of clinic: | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Private clinic | 2,916 | 98.3 | 1,320 | 96.9 | 4,236 | 97.8 | Ref. | Ref. | Ref. | Ref. | Ref. | Ref. |
   Community health center | 10 | 0.3 | 8 | 0.6 | 18 | 0.4 | 0.58 | (0.14, 2.35) | 0.45 | 0.46 | (0.11, 2.01) | 0.30 |
   Hospital-based ambulatory clinic | 41 | 1.4 | 35 | 2.6 | 76 | 1.8 | 0.53 | (0.30, 0.93) | 0.03 | 0.75 | (0.37, 1.53) | 0.43 |
Geographic location of clinic: | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Urban | 2,476 | 83.5 | 1,169 | 85.8 | 3,645 | 84.2 | Ref. | Ref. | Ref. | Ref. | Ref. | Ref. |
   Rural | 491 | 16.6 | 194 | 14.2 | 685 | 15.8 | 1.20 | (0.99, 1.46) | 0.07 | 1.19 | (0.98, 1.45) | 0.08 |
Physician familiarity with the patient (patient treated by the study physician in the previous year): | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   No | 1,199 | 40.4 | 475 | 34.9 | 1,674 | 38.7 | Ref. | Ref. | Ref. | Ref. | Ref. | Ref. |
   Yes | 1,768 | 59.6 | 888 | 65.1 | 2,656 | 61.3 | 0.79 | (0.69, 0.91) | < 0.001 | 0.95 | (0.82, 1.11) | 0.53 |
Day of the week: | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Weekday | 2,797 | 94.3 | 1,308 | 96.0 | 4,105 | 94.8 | Ref. | Ref. | Ref. | Ref. | Ref. | Ref. |
   Weekend | 170 | 5.7 | 55 | 4.0 | 225 | 5.2 | 1.42 | (1.03, 1.95) | 0.03 | 1.28 | (0.92, 1.77) | 0.15 |
Season: | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Winter (12/22-03/20) | 737 | 24.8 | 339 | 24.9 | 1,076 | 24.9 | Ref. | Ref. | Ref. | Ref. | Ref. | Ref. |
   Spring (03/21-06/20) | 855 | 28.8 | 317 | 23.3 | 1,172 | 27.1 | 1.22 | (1.02, 1.47) | 0.03 | 1.29 | (1.07, 1.57) | 0.01 |
   Summer (06/21-09/22) | 645 | 21.7 | 351 | 25.8 | 996 | 23.0 | 0.84 | (0.70, 1.01) | 0.06 | 0.91 | (0.75, 1.10) | 0.33 |
   Fall (09/23-12/21) | 730 | 24.6 | 356 | 26.1 | 1,086 | 25.1 | 0.94 | (0.79, 1.12) | 0.48 | 0.97 | (0.81, 1.17) | 0.79 |
 | Mean | SD | Mean | SD | Mean | SD |  |  |  |  |  |  |
No. visits for the same syndrome billed by the study physician in the previous 30 days (per 10 visits) | 4.1 | 6.7 | 4.2 | 6.2 | 4.2 | 6.6 | 1.08 | (0.95, 1.23) | 0.25 | 1.05 | (1.01, 1.08) | 0.01 |
Physician workload: no. claims billed that day (per 10 claims) | 35.1 | 17.4 | 36.5 | 21.0 | 35.5 | 18.6 | 0.96 | (0.93, 1.00) | 0.03 | 0.93 | (0.90, 0.97) | < 0.001 |