Table 3.
Prevalence Ratios of Alternate Adherence Measures in Relation to the Outcome of Nonadherence by Urine Testinga and Area Under the Receiver Operating Characteristic Curve for Each Measure
| Alternate Adherence Measure | Nonadherent Participants by the Urine Test,b No. (%) | Prevalence Ratioc (95% CI) | P Value | Area Under the Receiver Operating Characteristic Curved |
|---|---|---|---|---|
| 99DOTS patient-reported doses alone (n=608)e | 0.66 | |||
| 0 days nonengagement | 9/138 (6.5) | Ref | ||
| 1 day nonengagement | 11/211 (5.2) | 0.8 (0.3–1.9) | .607 | |
| 2 days nonengagement | 10/68 (14.7) | 2.3 (1.0–5.3) | .062 | |
| 3 days nonengagement | 37/191 (19.4) | 3.0 (1.5–6.0) | .002∗ | |
| 99DOTS patient- and provider-reported (n=608)e | 0.62 | |||
| 0 days nonengagement | 28/314 (8.9) | Ref | ||
| 1 day nonengagement | 17/212 (8.0) | 0.9 (0.5–1.6) | .718 | |
| 2 days nonengagement | 5/14 (35.7) | 4.0 (1.8–8.8) | .001∗ | |
| 3 days nonengagement | 17/68 (25.0) | 2.9 (1.6–4.8) | <.001∗ | |
| Pill estimate (n=650) | 0.55 | |||
| Taken as expected | 61/570 (10.7) | Ref | ||
| Excess of pills | 12/67 (17.9) | 1.7 (1.0–2.9) | .074 | |
| Shortage of pills | 4/13 (30.8) | 2.9 (1.2–6.7) | .015∗ | |
| 4-day recall (n=650) | 0.60 | |||
| 0 doses missed | 59/614 (9.6) | Ref | ||
| 1 dose missed | 8/19 (42.1) | 4.4 (2.5–7.8) | <.001∗ | |
| 2 doses missed | 4/9 (44.4) | 4.6 (2.1–10.0) | <.001∗ | |
| 3 or 4 doses missed | 6/8 (75.0) | 7.8 (4.9–12.5) | <.001∗ | |
| Last missed dose question (n=650) | 0.67 | |||
| Never skip medications | 37/483 (7.7) | Ref | ||
| Within the past week | 19/47 (40.4) | 5.3 (3.3–8.4) | <.001∗ | |
| 1–2 weeks ago | 5/34 (14.7) | 1.9 (0.8–4.6) | .14 | |
| 2–4 weeks ago | 8/40 (20.0) | 2.6 (1.3–5.2) | .007∗ | |
| 1–3 months ago | 7/35 (20.0) | 2.6 (1.3–5.4) | .010∗ | |
| >3 months | 1/11 (9.1) | 1.2 (0.2–7.9) | .859 |
Abbreviations: AUC, area under the curve; Ref,reference group.
Indicates statistical significance at the 5% level.
Nonadherence by urine testing was defined as a yellow urine test result, as compared with a green or purple/blue result, which comprised adherence.
Number of nonadherent patients by urine testing divided by the number of patients in each alternate measure category.
Prevalence ratio refers to a ratio of proportions—that is, the proportion of participants with nonadherence by urine testing in each category over the proportion of participants with nonadherence by urine testing in the reference category.
AUCs are in relation to the categorical breakdown of variables presented in the table.
We excluded 42 participants who were eligible for 99DOTS and recruited into the study, but whose 99DOTS enrollment date in the electronic system was after the home visit date.