Table 1.
Characteristics of Study Population (n=9832)
| Type | Variables | Mean (S.D.) | Frequency (%) |
|---|---|---|---|
| Predisposing (pre-index period) | Age (years) | 44.81 (11.64) | – |
| Sex (female) | – | 7183 (73.06) | |
| Race | – | ||
| White | 5139 (52.27) | ||
| Black | 3096 (31.49) | ||
| Hispanic | 151 (1.54) | ||
| Others | 1239 (12.60) | ||
| Multiracial | 207 (2.11) | ||
| Need (pre-index period) | Diabetes severity | – | |
| Nephropathy | 152 (1.55) | ||
| Neuropathy | 506 (5.15) | ||
| Retinopathy | 152 (1.55) | ||
| Charlson Comorbidity Index Score (range: 0–35) | 0.709 (1.27) | – | |
| Elixhauser Index Score (range: 0–30) | 1.73 (1.55) | – | |
| Chronic Disease Scores (range: 0–18) | 4.64 (2.96) | – | |
| HRQL-CI Scores | – | ||
| Physical domain (range: 0–35) | 4.15 (3.69) | ||
| Mental domain (range: 0–25) | 3.65 (3.39) | ||
| Enabling (pre-index period) | Type of health plan | – | |
| Fee-for-service | 5448 (55.41) | ||
| Capitated plan | 3203 (32.58) | ||
| Both | 1181 (12.01) | ||
| Type of provider: at least 1 endocrinologist visit (yes/no) | – | 31 (0.32) | |
| Total no. of therapeutic classes | 10.82 (10.82) | – | |
| Total no. of drugs supplied | 557.35 (48.64) | – | |
| Physician's adherence to diabetes care (post-index period) | At least 2 HbA1c tests/year | 6950 (70.69) | |
| At least 1 LDL test/year | 6209 (63.15) | ||
| At least 1 nephropathy screening/year | 2326 (23.66) | ||
| At least 1 eye examination/year | 4297 (43.70) | ||
| Total physician treatment adherence score (range=0–4) | 2.51 (1.11) | ||
| Patient's adherence to diabetes medication (post-index period) | Overall adherence (MPR) for 3 selected OADs (Met, Sulfa, TZD) (n=9832) | 0.81 (0.26) | – |
| MPR for monotherapy (n=7888) | 0.78 (0.23) | ||
| Met (n=62) | 0.70 (0.21) | ||
| Sulfa (n=5949) | 0.77 (0.24) | ||
| TZD (n=1877) | 0.81 (0.21) | ||
| MPR for fixed dose regimensa (n=290) | 0.78 (0.21) | ||
| MPR for switching or combination regimens (n=1645) | 0.95 (0.12) | ||
| Health care utilization | Total no. of hospital admissions | ||
| Pre-index period | 0.38 (0.09) | ||
| Post-index period | 0.35 (0.096) | ||
| Total no. of emergency room visits | |||
| Pre-index period | 0.23 (0.09) | ||
| Post-index period | 0.21 (0.74) | ||
| Total no. of outpatient visits | |||
| Pre-index period | 24.47 (14.85) | ||
| Post-index period | 27.43 (17.45) | ||
| Health care costs | Total costs ($) | ||
| Pre-index period | 8318.34 (24,051) | ||
| Post-index period | 8807.67 (27,204) | ||
| Diabetes care-related costs ($) | |||
| Pre-index period | 1282.93 (8381) | ||
| Post-index period: | 2257.99 (9968) |
HRQL-CI, Health-related Quality of Life Comorbidity Index; LDL, low-density lipoprotein; Met, metformin; MPR, medication possession ratio; OAD, oral antidiabetic medication; Sulfa, sulfonylurea; TZD, thiazolidinediones; a:4 fixed-dose regimens are Glucovance, Avplusamet, Metaglip, and Actaoplus Met.