Table 3.
Variables associated with adherence to metformin (PDC ≥ 0.80).†
| All patients (N = 111,186) |
New metformin users (N = 7197) |
Ongoing metformin users (N = 76,854) |
||||
|---|---|---|---|---|---|---|
| Odds ratio | 95% CI | Odds ratio | 95% CI | Odds ratio | 95% CI | |
| Age | 1.021 | (1.020–1.023) | 1.018 | (1.013–1.023) | 1.022 | (1.020–1.023) |
| Male (Referent: Female) | 0.936 | (0.909–0.964) | – | 0.933 | (0.905–0.962) | |
| Smoker | 1.188 | (1.140–1.237) | 1.199 | (1.047–1.371) | 1.183 | (1.134–1.235) |
| HbA1c (Referent: HbA1c < 6.5) | ||||||
| 6.5–6.9 | 0.898 | (0.854–0.943) | – | 0.905 | (0.860–0.952) | |
| 7.0–7.9 | 0.888 | (0.848–0.930) | – | 0.894 | (0.853–0.937) | |
| 8.0–8.9 | 0.862 | (0.813–0.913) | 0.618 | (0.455–0.839) | 0.879 | (0.828–0.933) |
| BMI | 1.012 | (1.010–1.015) | – | 1.012 | (1.010–1.015) | |
| Baseline medications use (5–10 medications) | 1.073 | (1.035–1.112) | 1.256 | (1.074–1.468) | – | |
| Baseline use of anti-diabetic drugs | ||||||
| Sulfonylureas | 1.070 | (1.037–1.105) | – | 1.066 | (1.032–1.102) | |
| DPP-4 inhibitors | 1.091 | (1.046–1.138) | – | 1.085 | (1.041–1.132) | |
| Concomitant medication | ||||||
| Lipid-lowering therapy | 1.093 | (1.051–1.135) | – | 1.090 | (1.046–1.136) | |
| Diabetes-related comorbidities | ||||||
| Retinopathy | 0.946 | (0.915–0.978) | – | 0.934 | (0.903–0.966) | |
| Depression | 1.192 | (1.153–1.233) | 1.293 | (1.151–1.452) | 1.185 | (1.144–1.227) |
| Macrovascular disease | 1.185 | (1.144–1.228) | – | 1.192 | (1.149–1.236) | |
| Anxiety | 1.116 | (1.076–1.158) | – | 1.113 | (1.071–1.156) | |
| Chronic kidney disease | 1.106 | (1.064–1.150) | 1.340 | (1.143–1.571) | 1.094 | (1.051–1.138) |
| Hypoglycemia | 1.292 | (1.202–1.390) | – | 1.300 | (1.208–1.400) | |
| Neuropathy | 1.143 | (1.079–1.210) | – | 1.138 | (1.073–1.207) | |
| Obesity | 0.936 | (0.903–0.970) | 0.835 | (0.734–0.951) | 0.945 | (0.910–0.980) |
| Dementia | 2.270 | (2.016–2.555) | 2.115 | (1.379–3.244) | 2.282 | (2.017–2.582) |
| COPD | 1.211 | (1.140–1.286) | 1.502 | (1.219–1.851) | 1.190 | (1.117–1.267) |
BMI, body mass index; CI, confidence interval; COPD, chronic obstructive pulmonary disease.
†
Adherence in patients who did not discontinue. Shown are statistically significant values at P < 0.01. Odds ratio values differing from unity by ±10% are in bold font.