Table 2.

Factors Associated With Test Non-Completion

Variable	N = 52,407 drug-test pairs
Adjusted OR* [95 % CI†]
Patient gender
Male	1 [Reference]
Female	1.02 [0.93–1.11]
Patient age
< 40 years old	1.52 [1.27–1.83]
40–50	1.49 [1.28–1.74]
50–60	1.33 [1.18–1.50]
60–70	1.05 [0.93–1.19]
70–80	0.96 [0.87–1.07]
≥ 80	1 [Reference]
Number of patient visits
0–5 visits	1.41 [1.25–1.59]
6–10 visits	1.03 [0.92–1.16]
11–18 visits	0.99 [0.89–1.10]
≥ 19 visits	1 [Reference]
Patient medication burden
Single drug	1.26 [1.15–1.37]
>1 drug	1 [Reference]
Provider specialty
Specialist	1 [Reference]
PCP‡	1.17 [0.97–1.41]
Provider frequency of prescribing this drug
First quartile (once)	1 [Reference]
Second quartile (2–5 times)	0.76 [0.49–1.20]
Third quartile (6–46 times)	0.63 [0.42–0.96]
Fourth quartile (≥ 47 times)	0.67 [0.44–1.03]
Indication for monitoring test
Recommended test in PDR	1 [Reference]
BBW§	1.91 [1.66–2.19]
Clinical guidelines	0.80 [0.69–0.94]
Recommended test monitoring frequency
Yearly	1 [Reference]
More frequent	0.99 [0.79–1.24]
Number of recommended tests for medication
Single	1 [Reference]
Multiple	0.69 [0.59–0.80]
Prescription type
Chronic use	1 [Reference]
New use	2.57 [2.35–2.82]

^*OR, odds ratio; ^†CI, confidence interval; ^‡PCP, primary care provider; ^§BBW, black box warning