Table 3.
Association between Test Ordering and Covariates (Visits to Specialist Owners in Group Practices)
| CBC Adjusted OR (95% CI)a | Electrolytes Adjusted OR (95% CI)a | HbA1c Adjusted OR (95% CI)a | Cholesterol Adjusted OR (95% CI)a | PSA Adjusted OR (95% CI)a | |
|---|---|---|---|---|---|
| On-Site Lab | |||||
| No | ref | ref | ref | ref | ref |
| Yes | 7.8 (4.8–12.7) | 3.4 (1.9–6.3) | 5.1 (1.8–14.9) | 3.3 (1.8–6.0) | 3.6 (1.8–7.1) |
| Age | |||||
| Age <50 | ref | ref | ref | ref | ref |
| Age ≥50 | 1.1 (0.9–1.5) | 1.1 (0.8–1.5) | 1.0 (0.5–2.0) | 1.1 (0.8–1.4) | 3.8 (1.9–7.6)a |
| Patient Sex | |||||
| Female | ref | ref | ref | ref | ref |
| Male | 0.8 (0.6–1.0) | 0.8 (0.6–1.1) | 1.1 (0.6–1.9) | 1.2 (0.9–1.5) | 4.5 (3.1–6.6) |
| Patient Race | |||||
| White | ref | ref | ref | ref | ref |
| Black | 1.4 (1.0–2.1) | 1.1 (0.6–2.0) | 1.6 (0.8–3.0) | 0.8 (0.4–1.7) | 0.8 (0.5–1.4) |
| Other | 0.9 (0.5–1.5) | 0.8 (0.4–1.9) | 1.6 (0.7–3.4) | 1.2 (0.7–2.2) | 0.5 (0.2–1.4) |
| Patient Ethnicity | |||||
| Hispanic | ref | ref | ref | ref | ref |
| Non Hispanic | 1.1 (0.5–2.3) | 0.6 (0.3–1.3) | 0.4 (0.2–1.1) | 0.8 (0.5–1.5) | 0.8 (0.4–1.2) |
| Patient Insurance Status | |||||
| Private | ref | ref | ref | ref | ref |
| Medicare | 1.0 (0.8–1.2) | 0.9 (0.7–1.3) | 1.1 (0.5–2.2) | 1,2 (0.9–1.6) | 1.2 (0.9–1.6) |
| Medicaid | 0.9 (0.6–1.2) | 0.4 (0.2–1.3) | 1.6 (0.6–4.0) | 0.9 (0.5–1.9) | 0.5 (0.3–1.1) |
| Other | 0.8 (0.4–1.4) | 0.5 (0.2–1.3) | 0.9 (0.3–2.3) | 0.7 (0.3–1.5) | 0.7 (0.4–1.4) |
| Major Reason for Visit | |||||
| Acute | ref | ref | ref | ref | ref |
| Chronic | 1.3 (1.0–1.8) | 1.2 (0.8–1.9) | 1.9 (0.9–4.1) | 1.4 (0.8–2.5) | 2.3 (1.5–3.4) |
| Preventative | 0.6 (0.3–1.2) | 0.4 (0.2–0.9) | 0.6 (0.2–2.0) | 1.0 (0.5–2.0) | 2.5 (1.1–5.6) |
| Other | 0.5 (0.3–0.7) | 0.4 (0.2–0.8) | 0.7 (0.2–2.7) | 0.4 (0.2–0.8) | 0.6 (0.4–1.1) |
| Patient Number of Chronic Conditions | |||||
| 0 | ref | ref | ref | ref | ref |
| 1–3 | 2.2 (1.5–3.2) | 3.7 (1.8–7.5) | 2.8 (1.1–6.7) | 4.0 (2.5–6.5) | 0.7 (0.5–0.9) |
| >3 | 2.4 (1.3–4.6) | 6.9 (2.7–17.5) | 5.8 (2.2–15.0) | 5.6 (2.6–12.2) | 0.6 (0.3–1.2) |
| Practice Location in an MSA | |||||
| Yes | ref | ref | ref | ref | ref |
| No | 0.2 (0.1–0.4) | 0.1 (0.0–0.6) | 0.1 (0.0–0.6) | 0.1 (0.0–0.3) | 1.1 (0.5–2.4) |
| Practice Census Region | |||||
| Northeast | ref | ref | ref | ref | ref |
| Midwest | 1.7 (0.8–3.6) | 0.9 (0.4–2.2) | 1.0 (0.1–7.5) | 0.9 (0.4–2.4) | 1.8 (0.6–5.1) |
| South | 1.4 (0.7–2.9) | 0.8 (0.4–1.7) | 0.9 (0.3–3.1) | 0.6 (0.3–1.4) | 1.1 (0.4–2.8) |
| West | 2.1 (1.0–4.0) | 1.5 (0.6–3.9) | 4.0 (1.3–12.6) | 1.8 (0.8–3.9) | 2.3 (0.7–8.0) |
| Practice EMRCapacity | |||||
| Yes | ref | ref | ref | ref | ref |
| Partial | 1.8 (0.8–4.0) | 2.9 (0.8–10.1) | 3.3 (0.7–15.9) | 1.9 (0.7–4.7) | 1.2 (0.4–3.3) |
| No | 1.2 (0.7–1.9) | 1.7 (0.7–3.7) | 1.8 (0.6–5.4) | 1.2 (0.6–2.2) | 1.0 (0.4–2.2) |
aAdjusted for patient sex, age, race, ethnicity, number of chronic conditions, major reason for visit, geographic region, urban or rural location, and presence of an electronic medical record
Bold-faced type indicates p < 0.01