Table 1

Selected characteristics of individuals with diabetes and controls, frequency-matched to cases (5:1) on age, sex and year of diagnosis or control selection date

VariableCasesControlsP value*
Unique persons15 88865 084NA
Number15 88879 435NA
Sex, female, n (COL %)7798 (49.1)38 988 (49.1)Matched
Age at diagnosis or control selection date, years, mean (SD)54.9 (15.1)54.9 (15.3)Matched
Age, years, categories, n (COL %)Matched
 10–<20 years304 (1.9)1520 (1.9)
 20–<30 years628 (4.0)3140 (4.0)
 30–<40 years1611 (10.1)8055 (10.1)
 40–<50 years3086 (19.4)15 429 (19.4)
 50–<60 years4286 (27.0)21 428 (27.0)
 60–<70 years3510 (22.1)17 548 (22.1)
 70–<80 years1737 (10.9)8685 (10.9)
 80–<90 years645 (4.1)3225 (4.1)
 ≥90 years81 (0.5)405 (0.5)
Race, white, n (COL %)15 429 (97.1)77 867 (98.0)<0.001
Hispanic ethnicity, n (COL %)369 (2.3)1094 (1.4)<0.001
Primary care provider†, yes, n (%)11 884 (74.8)61 042 (76.9)<0.001
Year of diagnosis/encounter, n (COL %)Matched
 20081761 (11.1)8805 (11.1)
 20092019 (12.7)10 095 (12.7)
 20101747 (11.0)8735 (11.0)
 20111675 (10.5)8373 (10.5)
 20121716 (10.8)8579 (10.8)
 20131842 (11.6)9209 (11.6)
 20141844 (11.6)9220 (11.6)
 20151734 (10.9)8669 (10.9)
 20161550 (9.8)7750 (9.8)
Setting of diagnosis/encounter, n (COL %)<0.001
 Outpatient12 068 (76.0)73 998 (93.2)
 Medication order1632 (10.3)0 (0.0)
 Urgent care165 (1.0)2116 (2.7)
 Emergency department1526 (9.6)3068 (3.9)
 Inpatient498 (3.1)252 (0.3)
Outpatient encounters in year before diagnosis or control selection date, mean (SD)4.4 (5.1)3.5 (4.1)<0.001
Outpatient encounters, total before diagnosis or control selection date, mean (SD)35.9 (34.8)35.2 (32.5)0.01
Medical Assistance, % of time receiving, n (COL %)<0.001
 <50%14 921 (93.9)76 705 (83.7)
 ≥50%967 (6.1)2730 (3.4)
Outpatient encounters before diagnosis/encounter, mean (SD), by % of time receiving Medical Assistance<0.001
 0%35.5 (34.1)34.9 (32.1)
 0.1%–24.9%45.2 (40.7)42.8 (38.3)
 25.0%–74.9%33.9 (35.8)35.2 (33.6)
 75+%29.1 (26.9)27.7 (26.0)
Duration from first contact with health system to diagnosis/control selection date, years, n (%)0.72
 Quartile 1 (2–<5 years)1860 (11.7)9466 (11.9)
 Quartile 2 (5–<8 years)2571 (16.2)12 646 (15.9)
 Quartile 3 (8–<12 years)4700 (29.6)23 665 (29.8)
 Quartile 4 (≥12 years)6757 (42.5)33 658 (42.4)
Community socioeconomic deprivation, n (COL %)‡<0.001
 Quartile 13001 (18.9)17 329 (21.8)
 Quartile 24300 (27.1)23 172 (29.2)
 Quartile 34217 (26.5)20.328 (25.6)
 Quartile 44370 (27.5)18 606 (23.4)
Greenness, peak NDVI, in buffer, n (COL %) §<0.001
 Tertile 15894 (37.1)25 894 (32.6)
 Tertile 25023 (31.6)26.751 (33.7)
 Tertile 34971 (31.3)26 790 (33.7)
Administrative community type of residence, n (COL %)<0.001
 Borough4621 (29.1)21 756 (27.4)
 Census tract in city1806 (11.4)6548 (8.2)
 Township9461 (59.6)51 131 (64.4)
Setting of residence, n (COL %)<0.001
 Rural6513 (41.0)34 984 (44.0)
 Urbanised area4906 (30.9)23 423 (29.5)
 Urban cluster4469 (28.1)21 028 (26.5)
  • *Because controls could be in these comparisons more than once, methods were used for significance testing that accounted for this, including inverse-probability weighted regression for time-invariant characteristics, mixed-effect regression for time-varying continuous (linear), binary (logistic) and count (Poisson) characteristics, and multinomial logistic regression with robust SEs for polytomous time-varying characteristics. In the weighted analyses, weights were the number of appearances in the analysis (implemented with a dataset having only one record per person).

  • †According to Geisinger’s primary care provider lists.

  • ‡Quartile cutoffs were defined within the three time periods; the range of values for Q1, Q2, Q3 and Q4 were −18.33 to −1.96; −1.99 to −0.015; 0.005 to 2.05; and 2.11 to 12.4.

  • §The range of values in T1, T2 and T3 were 0.07 to 0.627, 0.63 to 0.756 and 0.76 to 0.94, respectively.

  • COL, column; NDVI, normalised difference vegetation index.