Table 1.
Demographics of the study cohort according to ever use of pioglitazone: the KPNC diabetes registry, 1997–2008
| Ever use of pioglitazone* | Never use of pioglitazone* | |
|---|---|---|
| N | 30,173 | 162,926 |
| Age (years) | ||
| 40–49 | 8,612 (28.5) | 36,452 (22.4) |
| 50–59 | 9,945 (33.0) | 41,962 (25.8) |
| 60–69 | 7,799 (25.8) | 42,691 (26.2) |
| ≥70 | 3,817 (12.7) | 41,821 (25.7) |
| Sex (female) | 14,157 (46.9) | 75,686 (46.5) |
| Race/ethnicity | ||
| White | 14,768 (48.9) | 80,777 (49.6) |
| Black | 2,823 (9.4) | 16,731 (10.3) |
| Asian | 3,834 (12.7) | 18,877 (11.6) |
| Hispanic | 3,320 (11.0) | 14,430 (8.9) |
| Other | 1,691 (5.6) | 8,876 (5.4) |
| Missing | 3,737 (12.4) | 23,235 (14.3) |
| Current smoker | 6,052 (20.1) | 28,023 (17.2) |
| Renal function | ||
| Normal creatinine | 23,174 (76.8) | 125,879 (77.3) |
| Elevated creatinine† | 1248 (4.1) | 13,993 (8.6) |
| Missing | 5,751 (19.1) | 23,054 (14.2) |
| Bladder condition‡ | 3,686 (12.2) | 25,581 (15.7) |
| Congestive heart failure | 969 (3.2) | 11,038 (6.8) |
| Income | ||
| Low§ | 14,413 (47.8) | 82,270 (50.5) |
| High | 12,825 (42.5) | 66,133 (40.6) |
| Missing | 2,935 (9.7) | 14,523 (8.9) |
| Baseline A1C (%) | ||
| <7 | 4,873 (16.2) | 46,407 (28.5) |
| 7–7.9 | 5,455 (18.1) | 31,517 (19.3) |
| 8–8.9 | 3,921 (13.0) | 17,060 (10.5) |
| 9–9.9 | 2,979 (9.9) | 11,524 (7.1) |
| ≥10 | 7,330 (24.3) | 28,017 (17.2) |
| Missing | 5,615 (18.6) | 28,401 (17.4) |
| Newly diagnosed with diabetes at the start of follow-up¶ | 14,687 (48.7) | 94,739 (58.1) |
| Duration of diabetes (years) | ||
| 0–5 | 17,363 (57.5) | 102,916 (63.2) |
| 5–9 | 2,983 (9.9) | 9,671 (5.9) |
| ≥10 | 2,956 (9.8) | 17,432 (10.7) |
| Missing | 6,871 (22.8) | 32,907 (20.2) |
| Other cancer prior to baseline | 1,186 (3.9) | 8,762 (5.4) |
| Other diabetes medications | ||
| Other TZDs | 2,754 (9.1) | 2,470 (1.5) |
| Metformin | 24,797 (82.2) | 70,956 (43.6) |
| Sulfonylureas | 26,311 (87.2) | 95,429 (58.6) |
| Other oral hypoglycemic drugs | 1,482 (4.9) | 1,865 (1.1) |
| Insulin | 13,123 (43.5) | 41,337 (25.4) |
| Pioglitazone use during follow-up | ||
| Time since starting pioglitazone (months) | 39.5 (1–102) | N/A |
| <18 | 7,245 (24.0) | N/A |
| 18–36 | 6,681 (22.1) | N/A |
| >36 | 16,247 (53.8) | N/A |
| Duration of therapy (months) | 24.1 (1–102) | N/A |
| <12 | 7,332 (24.3) | N/A |
| 12–24 | 7,677 (25.4) | N/A |
| >24 | 15,164 (50.3) | N/A |
| Cumulative dose (mg) | 17,670 (450–179,000) | N/A |
| 1–10,500 | 10,281 (34.1) | N/A |
| 10,501–28,000 | 9,667 (32.0) | N/A |
| >28,000 | 10,225 (33.9) | N/A |
Data are n (%) or median (range) unless otherwise indicated. N/A, not applicable.
*All comparisons have P values <0.01 except female sex (P = 0.46).
†Creatinine ≥1.4 mg/dL for women and ≥1.5 mg/dL for men.
‡History of urinary tract infections, urolithiasis, incontinence, and other bladder or urethral conditions.
§Low income defined as median household income in census block below the cohort average ($59,000).
¶Includes newly diagnosed patients and patients who newly enrolled in KPNC with an existing diagnosis of diabetes.