Table 1.
Characteristics of metformin never users and ever users.
| Variable | Never Users | Ever Users | SD | 95% CI of SD | |||
|---|---|---|---|---|---|---|---|
| (n = 15,799) | (n = 148,468) | ||||||
| n | % | n | % | Lower | Upper | ||
| Basic data | |||||||
| Age * (years) | 63.52 ± 10.43 | 61.77 ± 10.02 | −18.64 | −20.28 | −17.00 | ||
| Diabetes duration (years) * | 8.66 ± 2.31 | 9.67 ± 2.11 | 54.43 | 52.78 | 56.08 | ||
| Sex (men) | 9014 | 57.05 | 79,227 | 53.36 | −7.68 | −9.32 | −6.04 |
| Occupation | |||||||
| I | 6200 | 39.24 | 58,150 | 39.17 | |||
| II | 3179 | 20.12 | 34,292 | 23.10 | 7.90 | 6.26 | 9.54 |
| III | 3310 | 20.95 | 30,988 | 20.87 | 0.42 | −1.22 | 2.06 |
| IV | 3110 | 19.68 | 25,038 | 16.86 | −9.21 | −10.85 | −7.56 |
| Living region | |||||||
| Taipei | 5332 | 33.75 | 47,084 | 31.71 | |||
| Northern | 1614 | 10.22 | 16,930 | 11.40 | 4.16 | 2.52 | 5.80 |
| Central | 2742 | 17.36 | 27,167 | 18.30 | 2.36 | 0.72 | 4.00 |
| Southern | 2754 | 17.43 | 25,390 | 17.10 | 0.15 | −1.49 | 1.79 |
| Kao-Ping and Eastern | 3357 | 21.25 | 31,897 | 21.48 | 0.52 | −1.12 | 2.16 |
| Major comorbidities | |||||||
| Hypertension | 12,909 | 81.71 | 121,765 | 82.01 | −2.80 | −4.44 | −1.15 |
| Dyslipidemia | 11,450 | 72.47 | 123,483 | 83.17 | 32.38 | 30.73 | 34.02 |
| Obesity | 436 | 2.76 | 6797 | 4.58 | 10.71 | 9.07 | 12.35 |
| Diabetes-related complications | |||||||
| Nephropathy | 5431 | 34.38 | 40,602 | 27.35 | −27.84 | −29.48 | −26.19 |
| Peritoneal dialysis/hemodialysis | 1237 | 7.83 | 2231 | 1.50 | −50.29 | −51.94 | −48.64 |
| Diabetes with ophthalmic manifestations/diabetic retinopathy | 2840 | 17.98 | 47,581 | 32.05 | 32.87 | 31.23 | 34.51 |
| Glaucoma | 1822 | 11.53 | 17,868 | 12.03 | 1.23 | −0.41 | 2.87 |
| Cataract | 7196 | 45.55 | 69,901 | 47.08 | 1.06 | −0.58 | 2.70 |
| Blindness and low vision | 82 | 0.52 | 565 | 0.38 | −3.01 | −4.65 | −1.37 |
| Stroke | 5189 | 32.84 | 44,041 | 29.66 | −10.49 | −12.13 | −8.85 |
| Ischemic heart disease | 7502 | 47.48 | 68,162 | 45.91 | −6.95 | −8.59 | −5.31 |
| Peripheral arterial disease | 3636 | 23.01 | 38,379 | 25.85 | 3.65 | 2.01 | 5.29 |
| Antidiabetic drugs | |||||||
| Insulin | 1268 | 8.03 | 3374 | 2.27 | −40.01 | −41.66 | −38.37 |
| Sulfonylurea | 11,553 | 73.12 | 108,025 | 72.76 | 12.55 | 10.91 | 14.19 |
| Meglitinide | 1278 | 8.09 | 5810 | 3.91 | −24.69 | −26.33 | −23.05 |
| Acarbose | 1801 | 11.40 | 8103 | 5.46 | −22.00 | −23.64 | −20.36 |
| Rosiglitazone | 465 | 2.94 | 7360 | 4.96 | 10.98 | 9.34 | 12.62 |
| Pioglitazone | 392 | 2.48 | 3913 | 2.64 | 2.72 | 1.08 | 4.36 |
| Commonly encountered comorbidities | |||||||
| Chronic obstructive pulmonary disease | 7715 | 48.83 | 71,015 | 47.83 | −3.77 | −5.41 | −2.13 |
| Tobacco abuse | 429 | 2.72 | 5820 | 3.92 | 8.20 | 6.56 | 9.84 |
| Alcohol-related diagnoses | 1202 | 7.61 | 10,299 | 6.94 | −3.49 | −5.13 | −1.85 |
| Heart failure | 3328 | 21.06 | 25,419 | 17.12 | −18.27 | −19.91 | −16.63 |
| Gingival and periodontal diseases | 13,216 | 83.65 | 128,871 | 86.80 | 11.69 | 10.05 | 13.33 |
| Pneumonia | 2759 | 17.46 | 21,320 | 14.36 | −15.96 | −17.60 | −14.32 |
| Osteoporosis | 3571 | 22.60 | 30,299 | 20.41 | −6.26 | −7.90 | −4.62 |
| Rheumatologic diseases | 1176 | 7.44 | 10,456 | 7.04 | −3.30 | −4.94 | −1.66 |
| Liver cirrhosis | 1282 | 8.11 | 7961 | 5.36 | −15.49 | −17.13 | −13.85 |
| Other chronic non-alcoholic liver diseases | 1503 | 9.51 | 16,882 | 11.37 | 7.48 | 5.84 | 9.12 |
| Hepatitis B virus infection | 704 | 4.46 | 6028 | 4.06 | −4.36 | −6.00 | −2.72 |
| Hepatitis C virus infection | 1003 | 6.35 | 7772 | 5.23 | −7.54 | −9.18 | −5.90 |
| Human immunodeficiency virus infection | 18 | 0.11 | 94 | 0.06 | −3.51 | −5.15 | −1.87 |
| Organ transplantation | 137 | 0.87 | 380 | 0.26 | −12.54 | −14.18 | −10.90 |
| Commonly used medications in diabetes patients | |||||||
| Angiotensin converting enzyme inhibitor/angiotensin receptor blocker | 10,958 | 69.36 | 108,934 | 73.37 | 6.00 | 4.36 | 7.64 |
| Calcium channel blocker | 9879 | 62.53 | 89,335 | 60.17 | −9.32 | −10.96 | −7.68 |
| Statin | 8568 | 54.23 | 98,307 | 66.21 | 27.60 | 25.95 | 29.24 |
| Fibrate | 5416 | 34.28 | 64,562 | 43.49 | 20.53 | 18.89 | 22.17 |
| Aspirin | 9024 | 57.12 | 91,731 | 61.79 | 8.20 | 6.56 | 9.84 |
SD: standardized difference, CI: confidence interval. * Age and diabetes duration are expressed as mean ± standard deviation. Refer to Materials and Methods for the classification of occupation.