Table 2.
Unadjusted and Adjusted Hazard Ratios and 95 % CIs of Independent Predictors of Antihypertensive Medication Initiation (All patients aged 18 years and older, N = 10,022)
| Variable | Unadjusted HR (95 % CI) | P value | Adjusted HR (95 % CI) | P value* | ||
|---|---|---|---|---|---|---|
| PATIENT FACTORS | ||||||
| Age | ||||||
| 18–39 years | 0.57 | (0.49–0.65) | < 0.001 | 0.56 | (0.47–0.67) | < 0.001 |
| 40–59 years | 0.73 | (0.65–0.81) | < 0.001 | 0.75 | (0.66–0.85) | < 0.001 |
| ≥ 60 years (reference) | 1.0 | ─ | ─ | 1.0 | ─ | ─ |
| Race/Ethnicity | ||||||
| White | ─ | ─ | 0.84 | (0.71–1.00) | 0.05 | |
| Non-White† (reference) | ─ | ─ | 1.0 | ─ | ─ | |
| Marital status | ||||||
| Single (reference) | ─ | ─ | 1.0 | ─ | ─ | |
| Married/Partnered | ─ | ─ | 0.94 | (0.84–1.05) | 0.30 | |
| Primary Spoken Language | ||||||
| English (reference) | ─ | ─ | 1.0 | ─ | ─ | |
| Other | ─ | ─ | 1.25 | (0.96–1.61) | 0.09 | |
| Tobacco Use | ||||||
| Current Tobacco Use (reference) | ─ | ─ | 1.0 | ─ | ─ | |
| Former Tobacco Use | ─ | ─ | 0.91 | (0.76–1.08) | 0.29 | |
| Never Used Tobacco | ─ | ─ | 0.87 | (0.74–1.02) | 0.10 | |
| Unknown/Missing | ─ | ─ | 1.32 | (1.10–1.59) | 0.003 | |
| Body mass index, kg/m2 | ─ | ─ | 1.014 | (1.006–1.021) | < 0.001 | |
| On Medicaid Ever‡ | ─ | ─ | 1.37 | (1.12–1.67) | 0.002 | |
| JNC 7 Stage of Hypertension§ | ||||||
| Stage 1: 140–159/90–99 mmHg | ─ | ─ | 0.63 | (0.56–0.71) | < 0.001 | |
| Stage 2: ≥ 160/100 mmHg (reference) | ─ | ─ | 1.0 | ─ | ─ | |
| Baseline Comorbid Conditions | ||||||
| Anxiety | ─ | ─ | 1.17 | (1.00–1.37) | 0.06 | |
| Depression | ─ | ─ | 0.93 | (0.74–1.15) | 0.48 | |
| Hyperlipidemia | ─ | ─ | 1.01 | (0.89–1.15) | 0.84 | |
| Diabetes mellitus | ─ | ─ | 1.44 | (1.18–1.76) | < 0.001 | |
| Low prevalence condition‖ | ─ | ─ | 1.26 | (1.04–1.51) | 0.02 | |
| ACG¶ Risk Score, young index | ─ | ─ | 1.06 | (1.02–1.10) | 0.003 | |
| Baseline Ambulatory Visit Counts, annual mean | ||||||
| Primary Care Visits | ─ | ─ | 1.06 | (1.04–1.09) | < 0.001 | |
| Specialty Care Visits | ─ | ─ | 1.08 | (1.06–1.10) | < 0.001 | |
| PROVIDER FACTORS | ||||||
| Primary Care Specialty | ||||||
| Internal Medicine (reference) | ─ | ─ | 1.0 | ─ | ─ | |
| Family Medicine/Family Practice | ─ | ─ | 0.95 | (0.84–1.07) | 0.40 | |
| Other# | ─ | ─ | 1.03 | (0.87–1.22) | 0.71 | |
| Provider Age**, years | ─ | ─ | 0.992 | (0.987–0.997) | 0.002 | |
Bold = significant at p <0.05
*Global p value for proportional hazards assumption p = 0.11
†Non-White: Black (4.9 %), Hispanic/Latino (1.9 %), Asian (1.6 %), Native Hawaiian/Pacific Islander (0.4 %), American Indian/Alaska Native (0.3 %); Unknown (2.9 %)
‡On Medicaid at any point during the baseline or study period
§JNC 7 Stage of Hypertension = severity of blood pressure elevation at study entry
‖Due to low prevalence, an indicator variable was created for the presence of any of the following: atrial fibrillation, congestive heart failure, stroke/transient ischemic attack, ischemic heart disease, peripheral vascular disease, collagen vascular disease, deficiency anemia, or chronic kidney disease
¶ACG = Adjusted Clinical Group Case-Mix Assessment System
#Other = Pediatrics/Adolescent Medicine, Obstetrics/Gynecology, and Geriatrics
**AMA is the source for the raw physician data (provider ages only); statistics, tables, or tabulations were prepared by User-Customer (M. Smith; PI: H. Johnson) using 2011 AMA Masterfile data.