Table 2.
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 (1.03, 1.19) † | 1.12 (1.04, 1.21) † | 1.05 (0.99, 1.12) | |||
65–74 | 1.13 (1.05, 1.22) † | 1.14 (1.05, 1.24) † | 1.06 (0.98, 1.14) | |||
≥75 | 1.06 (0.98, 1.15) § | 1.07 (0.98, 1.17) § | 0.98 (0.91, 1.06) ‡§ | |||
| ||||||
Sex | <0.01 | <0.01 | <0.01 | |||
Female | Reference | Reference | Reference | |||
Male | 1.06 (1.03, 1.10) † | 1.07 (1.03, 1.10) † | 1.06 (1.02, 1.09) † | |||
| ||||||
Race/ethnicity | <0.01 | <0.01 | <0.01 | |||
Non-Hispanic White | Reference | Reference | Reference | |||
Non-Hispanic Black | 1.09 (1.04, 1.15) † | 1.10 (1.04, 1.16) † | 1.09 (1.05, 1.14) † | |||
Hispanic | 1.11 (1.04, 1.17) † | 1.10 (1.03, 1.17) † | 1.11 (1.04, 1.19) † | |||
Others | 1.08 (1.01, 1.17) † | 1.09 (1.01, 1.18) † | 1.08 (1.00, 1.16) † | |||
| ||||||
Expected sources of payment | <0.01 | 0.02 | <0.01 | |||
Private | Reference | Reference | Reference | |||
Medicaid | 1.07 (1.02, 1.13) † | 1.07 (1.01, 1.13) † | 1.05 (0.99, 1.11) | |||
Medicare | 1.04 (0.99, 1.09) | 1.04 (0.99, 1.09) | 1.01 (0.97, 1.05) | |||
Self-pay | 1.10 (1.01, 1.19) † | 1.10 (1.01, 1.19) † | 1.12 (1.05, 1.20) †§ | |||
Others | 1.12 (1.04, 1.20) †§ | 1.12 (1.05, 1.20) †§ | 1.10 (1.04, 1.16) †§ | |||
| ||||||
Region | 0.90 | 0.65 | 0.64 | |||
Northeast | Reference | Reference | Reference | |||
Midwest | 0.98 (0.93, 1.03) | 0.99 (0.94, 1.04) | 0.98 (0.93, 1.04) | |||
South | 0.99 (0.94, 1.05) | 0.98 (0.93, 1.04) | 1.01 (0.95, 1.08) | |||
West | 0.99 (0.94, 1.04) | 0.96 (0.91, 1.02) | 0.98 (0.92, 1.04) | |||
| ||||||
Number of clinic visits in the past 12 months | <0.01 | 0.07 | ||||
0 (new patient) | Reference | Reference | ||||
1–2 | 0.93 (0.85, 1.01) | 0.94 (0.87, 1.03) | ||||
3–5 | 0.97 (0.90, 1.05) | 0.99 (0.92, 1.06) | ||||
≥ 6 | 0.91 (0.84, 0.98) †§ | 0.94 (0.87, 1.01) § | ||||
| ||||||
Number of diagnoses | <0.01 | <0.01 | ||||
1 | Reference | Reference | ||||
2 | 1.34 (1.23, 1.47) † | 1.23 (1.14, 1.32) † | ||||
3 | 1.49 (1.37, 1.62) †‡ | 1.29 (1.20, 1.38) †‡ | ||||
| ||||||
Number of medications | <0.01 | <0.01 | ||||
0–2 | Reference | Reference | ||||
3–5 | 1.28 (1.20, 1.38) † | 1.19 (1.11, 1.26) † | ||||
7–8 | 1.41 (1.33, 1.51) †‡ | 1.33 (1.26, 1.41) †‡ | ||||
| ||||||
Blood test for glucose ordered | <0.01 | <0.01 | ||||
No | Reference | Reference | ||||
Yes | 1.19 (1.15, 1.24) † | 1.10 (1.05, 1.16) † | ||||
| ||||||
Hemoglobin A1c ordered | <0.01 | <0.01 | ||||
No | Reference | Reference | ||||
Yes | 1.26 (1.21, 1.30)† | 1.19 (1.14, 1.25) † | ||||
| ||||||
Lipids/cholesterol ordered | <0.01 | 0.08 | ||||
No | Reference | Reference | ||||
Yes | 1.16 (1.12, 1.20)† | 0.95 (0.90, 1.01) | ||||
| ||||||
Disposition | <0.01 | 0.07 | ||||
Return at specific time | Reference | Reference | ||||
Refer to other physician | 0.99 (0.94, 1.05) | 0.98 (0.92, 1.03) | ||||
Refer to ER/Admit to hospital | 0.93 (0.76, 1.12) | 1.07 (0.94, 1.21) | ||||
Other | 0.81 (0.75, 0.87)†‡ | 0.92 (0.87, 0.98) † | ||||
| ||||||
Survey | 0.27 | 0.03 | 0.01 | |||
NAMCS | Reference | Reference | Reference | |||
NHAMCS-OPD | 0.97 (0.93, 1.02) | 0.95 (0.90, 1.00) † | 0.94 (0.89, 0.99) † | |||
| ||||||
Survey year | 0.32 | 0.40 | 0.57 | |||
2006 | Reference | Reference | Reference | |||
2007 | 0.96 (0.90, 1.03) | 0.96 (0.89, 1.02) | 0.97 (0.91, 1.04) | |||
2008 | 0.94 (0.88, 1.00)† | 0.94 (0.89, 1.00) | 0.95 (0.90, 1.01) | |||
2009 | 0.98 (0.92, 1.05) | 0.98 (0.91, 1.05) | 0.97 (0.91, 1.03) | |||
2010 | 0.99 (0.93, 1.06) | 0.99 (0.93, 1.05) | 0.97 (0.91, 1.04) |
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. The areas under the receiver-operating characteristic (ROC) curve were 0.571 and 0.698 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.