Table 3.
Univariate
|
Multivariate model A
|
Multivariate model B
|
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---|---|---|---|---|---|---|
PRR (95% C.I.) | P-value | PRR (95% C.I.) | P-value | PRR (95% C.I.) | P-value | |
Age, years | <0.01 | <0.01 | <0.01 | |||
18–44 | Reference | Reference | Reference | |||
45–64 | 1.11 (1.02, 1.22) † | 1.13 (1.04, 1.24) † | 1.08 (1.00, 1.17) | |||
65–74 | 1.11 (1.00, 1.23) † | 1.12 (1.01, 1.25) † | 1.07 (0.95, 1.18) | |||
≥75 | 0.98 (0.89, 1.08) ‡§ | 1.00 (0.90, 1.11) ‡§ | 0.94 (0.85, 1.04) ‡§ | |||
| ||||||
Sex | <0.01 | <0.01 | <0.01 | |||
Female | Reference | Reference | Reference | |||
Male | 1.08 (1.04, 1.13) † | 1.09 (1.04, 1.14) † | 1.07 (1.03, 1.11) † | |||
| ||||||
Race/ethnicity | <0.01 | <0.01 | <0.01 | |||
Non-Hispanic White | Reference | Reference | Reference | |||
Non-Hispanic Black | 1.13 (1.06, 1.21) † | 1.13 (1.06, 1.21) † | 1.11 (1.05, 1.18) † | |||
Hispanic | 1.18 (1.09, 1.28) † | 1.17 (1.08, 1.28) † | 1.17 (1.08, 1.27) † | |||
Others | 1.17 (1.06, 1.29) † | 1.20 (1.09, 1.33) † | 1.16 (1.05, 1.28) † | |||
| ||||||
Expected sources of payment | <0.01 | 0.03 | <0.01 | |||
Private | Reference | Reference | Reference | |||
Medicaid | 1.09 (1.02, 1.16) † | 1.08 (1.01, 1.16) † | 1.08 (1.01, 1.15) † | |||
Medicare | 1.01 (0.96, 1.07) ‡ | 1.05 (0.99, 1.12) | 1.02 (0.97, 1.09) | |||
Self-pay | 1.17 (1.05, 1.31) †§ | 1.16 (1.03, 1.29) † | 1.21 (1.10, 1.33) †‡§ | |||
Others | 1.17 (1.05, 1.32) †§ | 1.18 (1.05, 1.32) † | 1.14 (1.03, 1.25) † | |||
| ||||||
Region | 0.37 | 0.08 | 0.17 | |||
Northeast | Reference | Reference | Reference | |||
Midwest | 0.95 (0.87, 1.03) | 0.96 (0.88, 1.04) | 0.98 (0.89, 1.07) | |||
South | 0.98 (0.90, 1.07) | 0.96 (0.88, 1.05) | 1.00 (0.90, 1.10) | |||
West | 0.93 (0.85, 1.02) | 0.88 (0.80, 0.97) † | 0.91 (0.83, 1.01) | |||
| ||||||
Number of clinic visits in the past 12 months | <0.01 | 0.02 | ||||
0 (new patient) | Reference | Reference | ||||
1–2 | 0.99 (0.88, 1.11) | 1.02 (0.91, 1.15) | ||||
3–5 | 1.02 (0.92, 1.14) | 1.06 (0.96, 1.18) | ||||
≥6 | 0.88 (0.79, 0.98) †‡§ | 0.96 (0.86, 1.08) § | ||||
| ||||||
Number of diagnoses | <0.01 | <0.01 | ||||
1 | Reference | Reference | ||||
2 | 1.87 (1.61, 2.15) † | 1.71 (1.50, 1.94) † | ||||
3 | 2.31 (1.99, 2.67) †‡ | 2.06 (1.81, 2.35) †‡ | ||||
| ||||||
Blood test for glucose ordered | <0.01 | <0.01 | ||||
No | Reference | Reference | ||||
Yes | 1.32 (1.25, 1.39) † | 1.14 (1.06, 1.22) † | ||||
| ||||||
Hemoglobin A1c ordered | <0.01 | <0.01 | ||||
No | Reference | Reference | ||||
Yes | 1.44 (1.37, 1.51) † | 1.32 (1.24, 1.41) † | ||||
| ||||||
Lipids/cholesterol ordered | <0.01 | 0.11 | ||||
No | Reference | Reference | ||||
Yes | 1.27 (1.21, 1.34) † | 0.94 (0.87, 1.02) | ||||
| ||||||
Disposition | <0.01 | <0.01 | ||||
Return at specific time | Reference | Reference | ||||
Refer to other physician | 0.91 (0.83, 0.99) † | 0.87 (0.80, 0.95) † | ||||
Refer to ER/Admit to hospital | 0.67 (0.42, 1.08) † | 0.90 (0.61, 1.33) | ||||
Other | 0.73 (0.66, 0.81) †‡ | 0.87 (0.80, 0.95) † | ||||
| ||||||
Survey | 0.57 | 0.05 | 0.17 | |||
NAMCS | Reference | Reference | Reference | |||
NHAMCS-OPD | 0.98 (0.92, 1.05) | 0.94 (0.88, 1.00) † | 0.94 (0.87, 1.02) | |||
| ||||||
Survey year | 0.40 | 0.58 | 0.69 | |||
2006 | Reference | Reference | Reference | |||
2007 | 0.98 (0.88, 1.09) | 0.98 (0.88, 1.09) | 0.98 (0.89, 1.08) | |||
2008 | 0.94 (0.86, 1.01) | 0.95 (0.88, 1.03) | 0.95 (0.89, 1.02) | |||
2009 | 0.99 (0.90, 1.10) | 1.00 (0.90, 1.10) | 0.98 (0.89, 1.08) | |||
2010 | 1.00 (0.90, 1.10) | 1.00 (0.90, 1.10) | 0.99 (0.89, 1.09) |
Unknown/missing category for expected payment sources and for disposition were included in the models, although their predicted prevalence ratios are not shown in the table. Multivariate models A and B did not include the number of medications as an independent variable. The areas under the receiver-operating characteristic (ROC) curve were 0.572 and 0.724 for multivariate models A and B, respectively. P-values were estimated by Wald F-statistics for the overall significance of each variable. P-values for the pairwise comparisons for characteristics with more than two categories were estimated by t-statistics and are expressed with the following notations:
P<0.05 compared to the first category;
P<0.05 compared to the second category;
P<0.05 compared to the third category.
S.E.: standard error; ER: emergency room; PRR: predicted prevalence ratio.