Table 4.

Percent New-Use Determinations Exceeding the Upper Prediction Limits Proposed by Huestis et al., 1998 and Schwilke et al., 2011

		Used in Study	Sensitivity Analysis
Specimen Pairs	N†	95% PI	80% PI	90% PI	99% PI	0.5 Ratio	1.5 Ratio
Wk 1/Baseline	34	0	0	0	0	0	5.9
Wk 2/Wk 1	35	0	0	0	0	2.9	22.9
Wk 3/Wk 2††	37	5.4	8.1	5.4	2.8	5.4	35.1
Wk 4/Wk 3	34	0	0	0	0	0	25.7

Note.

^†The number of excluded pairs was as follows: Week 1/Baseline (3 pairs excluded because at least one specimen exceeded the LOQ); Week 2/Week 1 (2 pairs excluded because at least one specimen exceeded the LOQ)

^††Two participants reported resuming cannabis use after the Week 2 visit, and were therefore not included in subsequent data points.