Table 1:

Patient characteristics on index date of kidney function decline and at 361 days after the index date for persistent patients

CharacteristicNo. (%) of patients in propensity score–weighted cohort at index date*SMDNo. (%) of patients in propensity score–weighted cohort at 361 dSMD
Metformin
n = 24 883
Sulfonylureas
n = 24 998
Metformin
n = 12 571
Sulfonylureas
n = 12 637
Age, yr, median (IQR)70.7 (63.7–78.1)70.5 (63.7–78.1)0.00172.5 (65.4–79.5)72.2 (65.3–79.4)0.003
Sex, male24362 (97.9)24476 (97.9)0.00112334 (98.1)12406 (98.2)0.004
Race
 White20908 (84.0)21007 (84.0)0.00210918 (86.9)10982 (86.9)0.002
 Black3503 (14.1)3512 (14.0)1424 (11.3)1430 (11.3)
 Other472 (1.9)479 (1.9)229 (1.8)226 (1.8)
Time from cohort entry to kidney threshold, mo, median (IQR)14.2 (5.9–30.7)14.3 (6.1–30.9)0.01428.4 (18.9–45.4)28.6 (19.0–45.6)0.009
Year reached kidney threshold
 2002–20032815 (11.3)2808 (11.2)0.0271568 (12.5)1545 (12.2)0.038
 2004–20054308 (17.3)4268 (17.1)2236 (17.8)2234 (17.7)
 2006–20075005 (10.1)5216 (20.9)2722 (21.7)2853 (22.6)
 2008–20093726 (15.0)3781(15.1)1983 (15.8)1999 (15.8)
 2010–20113291 (13.2)3207 (12.8)1737 (13.8)1673 (13.2)
 2012–20132603 (10.5)2556 (10.2)1281(10.2)1254 (9.9)
 2014–20152164 (8.7)2181 (8.7)1038 (8.2)1076 (8.5)
 2016971 (3.9)981 (3.9)5 (0.0)3 (0.0)
Laboratory variables
 HbA1c, %, median (IQR)6.5 (6.1–7.1)6.5 (6.1–7.2)0.0076.5 (6.1–7.0)6.50 (6.0–7.1)0.007
 Missing HbA1C measure1011 (4.1)994 (4.0)0.004503 (4.0)488 (3.9)
 Historical eGFR before kidney threshold, mL/min/1.73 m2, median (IQR)§69.3 (64.5–76.6)69.3 (64.5–76.6)0.001
 eGFR at kidney threshold, mL/min/1.73 m2, median (IQR)55.6 (51.4–58.0)55.6 (51.4–58.0)0.00255.9 (52.2–58.1)55.8 (52.2–58.2)0.003
 eGFR at 361 days, mL/min/1.73 m2, median (IQR)63.5 (55.8–72.3)63.7 (55.7–72.3)0.007
 Missing eGFR293 (1.2)296 (1.2)0.001964 (7.7)957 (7.6)0.004
 Hemoglobin, g/dL, median (IQR)14.0 (13.0–15.1)14.1 (13.0–15.1)0.00313.9 (12.9–14.9)14.0 (12.9–15.0)0.004
 Missing hemoglobin1507 (6.1)1503 (6.0)0.002777 (6.2)792 (6.3)0.003
 Low-density lipoprotein, mmol/L, median (IQR)2.28 (1.81–2.82)2.28 (1.81–2.82)0.0022.18 (1.76–2.64)2.18 (1.76–2.67)0.001
 Missing low-density lipoprotein measure779 (3.1)781 (3.1)< 0.001310 (2.5)309 (2.4)0.004
Microalbumin-to-creatinine ratio stage
 Normal (< 30 mg/g)9616 (38.6)9670 (38.7)0.0035261 (41.9)5305 (42.0)0.003
 Microalbuminuria (30–300 mg/g)2775 (11.2)2771.0 (11.1)1516 (12.1)1523 (12.1)
 Macroalbuminuria (> 300 mg/g)788 (3.2)781.6 (3.1)370 (2.9)373 (3.0)
Missing microalbumin-to-creatinine ratio11703 (47.0)11775 (47.1)5424 (43.1)5436 (43.0)
Proteinuria by urinalysis
 Negative11736 (47.2)11787 (47.2)0.0026101 (48.5)6129 (48.5)0.002
 Urine protein trace or 1+3533 (14.2)3561 (14.2)1700 (13.5)1711 (13.5)
 Proteinuria present at 2+831 (3.3)838 (3.4)330 (2.6)330 (2.6)
 Proteinuria present at 3+ or 4+336 (1.3)336 (1.3)127 (1.0)126 (1.0)
Unknown urine protein measure8446 (33.9)8476 (33.9)4313 (34.3)4341 (34.4)
Clinical variables
 Systolic blood pressure, mm Hg, median (IQR)131 (119–142)131 (119–142)0.002132 (120–142)132 (121–142)0.005
 Diastolic blood pressure, mm Hg, median (IQR)72 (64–80)72 (64–80)0.00172 (64–79)72 (64–79)0.001
 BMI, median (IQR)30.3 (27.0–34.4)30.3 (27.0–34.3)0.00330.2 (27.0–34.2)30.2 (27.0–34.1)0.001
 Missing BMI measure4688 (18.8)4719 (18.9)0.0012290 (18.2)2306 (18.3)0.003
Baseline comorbidities
 Malignant disease2971 (11.9)2990 (12.0)0.0011622 (12.9)1622 (12.8)0.002
 Liver disease625 (2.5)621 (2.5)0.002230 (1.8)229 (1.8)0.001
 HIV89 (0.4)90 (0.4)0.00139 (0.3)40 (0.3)0.001
 Congestive heart failure3051 (12.3)3071 (12.3)0.0011580 (12.6)1592 (12.6)0.001
 Cardiovascular disease7935 (31.9)8006 (32.0)0.0033987 (31.7)4019 (31.8)0.002
 Stroke831 (3.3)827 (3.3)0.002399 (3.2)401 (3.2)< 0.01
 Transient ischemic attack322 (1.3)332 (1.3)0.003155 (1.2)153 (1.2)0.002
 Serious mental illness**4957 (19.9)5035 (20.1)0.0052401 (19.1)2430 (19.2)0.003
 Smoking3045 (12.2)3068 (12.3)0.0011262 (10.0)1263 (10.0)0.002
 Chronic obstructive pulmonary disease4284 (17.2)4321 (17.3)0.0022157 (17.2)2166 (17.1)< 0.01
 History of respiratory failure821 (3.3)821 (3.3)0.001543 (4.3)533 (4.2)0.005
 History of sepsis406 (1.6)414 (1.7)0.002291 (2.3)291 (2.3)0.001
 History of pneumonia1074 (4.3)1092 (4.4)0.003648 (5.2)640 (5.1)0.004
 Arrhythmia4387 (17.6)4418 (17.7)0.0012399 (19.1)2414 (19.1)< 0.01
 Cardiac valve disease919 (3.7)929 (3.7)0.001497 (4.0)503 (4.0)0.002
 Parkinson disease234 (0.9)237 (0.9)0.001162 (1.3)158 (1.3)0.003
 Urinary tract infection1055 (4.2)1067 (4.3)0.001640 (5.1)645 (5.1)0.001
 Osteomyelitis156 (0.6)154 (0.6)0.00265 (0.5)64 (0.5)0.002
 Osteoporosis200 (0.8)206 (0.8)0.002118 (0.9)115 (0.9)0.003
 Falls57 (0.2)59 (0.2)0.00259 (0.5)57 (0.4)0.003
 Fractures556 (2.2)556 (2.2)0.001315 (2.5)313 (2.5)0.002
 Amputation118 (0.5)123 (0.5)0.00255 (0.4)55 (0.4)0.001
 Retinopathy286 (1.1)287 (1.1)< 0.001117 (0.9)121 (1.0)0.003
Use of medications
 Angiotensin-converting enzyme inhibitors15958 (64.1)16080 (64.3)0.0047623 (60.6)7690 (60.9)0.004
 Angiotensin II receptor blockers2904 (11.7)2904 (11.6)0.0021647 (13.1)1644 (13.0)0.003
 β-blockers12699 (51.0)12770 (51.1)0.0016533 (52.0)6565 (51.9)< 0.01
 Calcium-channel blockers7417 (29.8)7454 (29.8)< 0.0013801 (30.2)3820 (30.2)< 0.01
 Thiazide- and potassium-sparing diuretics10072 (40.5)10169 (40.7)0.0044531 (36.0)4578 (36.2)0.004
 Loop diuretics5059 (20.3)5087 (20.3)< 0.0012433 (19.4)2448 (19.4)0.001
 Other antihypertensive medications6873 (27.6)6887 (27.6)0.0023834 (30.5)3834 (30.3)0.003
 Statin lipid-lowering drugs16763 (67.4)16917 (67.7)0.0079059 (72.1)9119 (72.2)0.002
 Nonstatin lipid-lowering agents4237 (17.0)4264 (17.1)0.0012275 (18.1)2280 (18.0)0.002
 Antiarrhythmic drugs, digoxin and inotropes2313 (9.3)2321 (9.3)< 0.0011072 (8.5)1078 (8.5)< 0.01
 Anticoagulant drugs and platelet inhibitors2578 (10.4)2588 (10.4)< 0.0011386 (11.0)1394 (11.0)< 0.01
 Nitrates3652 (14.7)3689 (14.8)0.0021716 (13.6)1739 (13.8)0.003
 ASA5332 (21.4)5385 (21.5)0.0032533 (20.1)2570 (20.3)0.005
 Non-ASA platelet inhibitors2643 (10.6)2660 (10.6)0.0011329 (10.6)1343 (10.6)0.002
 Antipsychotic drugs1662 (6.7)1685 (6.7)0.003747 (5.9)745 (5.9)0.002
 Oral glucocorticoids1823 (7.3)1845 (7.4)0.002894 (7.1)892 (7.1)0.002
Indicators of health care use††
 Admitted to hospital within year (Veterans Health)3550 (14.3)3600 (14.4)0.0041510 (12.0)1538 (12.2)0.005
 Admitted to hospital in 30 days (Veterans Health)934 (3.8)953 (3.8)0.003188 (1.5)187 (1.5)0.001
 Admitted to hospital within year (Medicare/Medicaid)2851 (11.5)2860 (11.4)< 0.0011521 (12.1)1507 (11.9)0.005
 Admitted to hospital in 30 days (Medicare/Medicaid)450 (1.8)461 (1.8)0.003197 (1.6)198 (1.6)< 0.01
 Medicaid use in previous year298 (1.2)307 (1.2)0.003143 (1.1)142 (1.1)0.001
 Medicare use in previous year9128 (36.7)9129 (36.5)0.0035221 (41.5)5213 (41.3)0.006
 Nursing home encounter in previous year97 (0.4)102 (0.4)0.00366 (0.5)67 (0.5)< 0.01
 Medicare Advantage use3979 (16.0)3998 (16.0)< 0.0012498 (19.9)2517 (19.9)0.001
  • Note: ASA = acetylsalicylic acid, BMI = body mass index, eGFR = estimated glomerular filtration rate, IQR = interquartile range, SMD = standardized mean difference.

  • * Unless indicated otherwise.

  • Standardized mean differences are the absolute difference in means or percentage divided by an evenly weighted pooled standard deviation, or the difference between groups in number of standard deviations. In the weighted cohort, all standardized differences were less than 0.01, suggesting there were no important imbalances.

  • Other races include American Indian or Alaska Native, Asian, and Native Hawaiian or Pacific Islander.

  • § Historical eGFR is the eGFR before the patient met the inclusion criteria of eGFR < 60 mL/min/1.73 m2; eGFR at kidney threshold indicates the eGFR when the patient met the inclusion criteria of eGFR < 60 mL/min/1.73 m2.

  • Malignant disease includes all types of cancer except nonmelanoma skin cancer.

  • ** Serious mental illness included schizophrenia, depression, bipolar disorder, dementia and post-traumatic stress disorder.

  • †† The Veterans Health Administration provides health care coverage for those who serve their country through military services. Medicare and Medicaid health services are federal health care programs for eligible people older than 65 years. Medicare Advantage is a Medicare plan offered by private insurers that provides hospital, outpatient and (usually) prescription drug coverage, supplanting benefits under other Medicare plans.