Table 7 Classical Test Theory –Summary for PRI Health and Addiction Risk Scales in Surveys 1 and 2
Proposed Scale (# items) | Range don’t know responses (%) | Min-Max Sum score | Mean Sum score (SD) | Range CITC | Ceiling/ Floor (%) | Skewness | Cronbach’s alpha | Mean IIC | Range IIC |
|---|---|---|---|---|---|---|---|---|---|
Survey 1 | |||||||||
Health Risk (18) | 11–15 | 18–90 | 54.4 (22.32) | 0.89–0.93 | 7/10 | 0.05 | 0.99 | 0.83 | 0.76–0.90 |
Addiction Risk (7) | 8–12 | 6–30 | 20.7 (7.50) | 0.90–0.93 | 8/20 | −0.41 | 0.98 | 0.87 | 0.82–0.91 |
Survey 2 | |||||||||
Health Risk (18) | 12–14 | 18–90 | 56.1 (20.46) | 0.88–0.92 | 5/10 | 0.02 | 0.99 | 0.81 | 0.75–0.89 |
Addiction Risk (7) | 8–13 | 6–30 | 20.6 (7.09) | 0.92–0.95 | 6/18 | −0.32 | 0.98 | 0.89 | 0.85–0.93 |