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. 2016 Jul 31;2016:2656814. doi: 10.1155/2016/2656814

Table 1.

Characteristics of the study cohort elderly Medicare beneficiaries with diabetes and incident prostate cancer by metformin use SEER-Medicare linked database, 2007–2010.

All Overall Metformin users Non-metformin-user Sig.
N % N % N %
2,652 100 948 35.7 1,704 64.3
Predisposing characteristics

Age at diagnosis, in years ∗∗∗
 66–74 1,579 59.5 609 64.2 970 56.9
 75+ 1,073 40.5 339 35.8 734 43.1
Race/ethnicity
 Whites 1,914 72.2 680 71.7 1,234 72.4
 African American 323 12.2 108 11.4 215 12.6
 Hispanic/Latino 150 5.7 70 7.4 80 4.7
 Others 265 10.0 90 9.5 175 10.3
Marital status
 Unmarried 222 8.4 73 7.7 149 8.7
 Married 1,550 58.4 581 61.3 969 56.9
 Divorced/separated 393 14.8 136 14.3 257 15.1
 Others 487 18.4 158 16.7 329 19.3

Enabling characteristics

Quartile of median census of 2000 income
 $7–$34,522 664 25.0 265 28.0 399 23.4
 $34,523–46,224 664 25.0 243 25.6 421 24.7
 $46,229–62,764 664 25.0 229 24.2 435 25.5
 $62,767–200,008 660 24.9 211 22.3 449 26.3
Quartile of median census of 2000 education
 0–8.52 666 25.1 222 23.4 444 26.1
 8.53–15.16 655 24.7 229 24.2 426 25.0
 15.17–26.09 664 25.0 248 26.2 416 24.4
 26.1–100 667 25.2 249 26.3 418 24.5
PSA screening
 Yes 2,415 91.1 872 92.0 1,543 90.6
 No 237 8.9 76 8.0 161 9.4
Visit to a PCP
 Yes 1,858 70.1 672 70.9 1,186 69.6
 No 794 29.9 276 29.1 518 30.4
Statin use ∗∗∗
 Yes 1,576 59.4 656 69.2 920 54.0
 No 1,076 40.6 292 30.8 784 46.0
Insulin ∗∗∗
 Yes 102 3.8 62 6.5 40 2.3
 No 2,550 96.2 886 93.5 1,664 97.7

External environment characteristics

SEER-regions ∗∗
 Northeast 487 18.4 146 15.4 341 20.0
 South 570 21.5 223 23.5 347 20.4
 North-central 351 13.2 112 11.8 239 14.0
 West 1,244 46.9 467 49.3 777 45.6

Need characteristics

DCSI quartile ∗∗
 0 to 0 846 31.9 305 32.2 541 31.7
 1 to 1 476 17.9 195 20.6 281 16.5
 2 to 3 811 30.6 297 31.3 514 30.2
 4 to 13 519 19.6 151 15.9 368 21.6

Notes: based on the data of 2,652 elderly men aged 66 years and older diagnosed with prostate cancer between 2008 and 2009 using a surveillance, epidemiology, and end-results- (SEER-) Medicare linked Part D data. Significant group differences by metformin use are based on chi-square tests. % represented in the column is row percentages.

DCSI: diabetes complication severity index; PCP: primary care physician; PSA: prostate specific antigen; Sig.: level of significance. ∗∗∗ p < 0.001; ∗∗0.001 ≤ p < 0.01; 0.01 ≤ p < 0.05.