Table 1.

Possible Predictors of Ambulatory Antibiotic Prescription for Upper Respiratory Infections in the United States, 1997 to 1999

PredictorsOffice Visit Sample for a URI [% (n)]Adjusted Odds Ratios* (95% CI) for Antibiotic Prescription
Age
 18–4447% (449)Referent
 45–6430% (287)0.96 (0.68 to 1.36)
 ≥6523% (220)0.80 (0.46 to 1.40)
Female vs male62% (593)1.03 (0.73 to 1.44)
Nonwhite race vs white13% (124)0.83 (0.50 to 1.36)
Hispanic ethnicity vs not Hispanic7% (67)0.17 (0.08 to 0.38)
Geographic region
 South36% (343)Referent
 Midwest26% (249)1.43 (0.85 to 2.41)
 Northeast19% (182)1.33 (0.76 to 2.32)
 West19% (182)1.24 (0.72 to 2.11)
Rural area vs urban22% (210)1.28 (0.80 to 2.05)
Reimbursement type
 Private insurance58% (555)Referent
 Medicare17% (163)1.11 (0.58 to 2.12)
 Medicaid8% (76)1.09 (0.54 to 2.20)
 Selfpay9% (86)1.30 (0.72 to 2.36)
 Other8% (76)1.17 (0.64 to 2.15)
HMO vs not HMO27% (258)0.94 (0.62 to 1.43)
Physician specialty
 General/family medicine53% (508)Referent
 General internal medicine36% (343)0.37 (0.18 to 0.76)
 Other specialties11% (105)0.78 (0.33 to 1.86)
Primary care physician for this patient vs not  primary care physician81% (774)1.70 (1.08 to 2.68)
Solo practice vs not solo practice40% (382)1.10 (0.76 to 1.61)
Visit duration
 ≤10 minutes36% (344)Referent
 10–15 minutes40% (382)0.99 (0.65 to 1.50)
 >15 minutes24% (230)1.08 (0.69 to 1.69)
X-ray during visit vs not X-ray9% (86)1.06 (0.64 to 1.74)
Year of survey
 199730% (287)Referent
 199840% (382)0.64 (0.36 to 1.15)
 199930% (287)0.50 (0.27 to 0.94)
Interaction terms:
 General internal medicine * year 19982.22 (0.92 to 5.35)
 General internal medicine * year 19992.02 (0.45 to 4.65)
 Other specialties * year 19981.44 (0.45 to 4.65)
 Other specialties * year 19991.51 (0.45 to 5.16)
  • * Adjusted odds ratios are reported from a logistic regression analysis using all variables reported in Table 1.