Table 1 Assessments, data collection and analyses of the two studies
Stage 1 | Stage 2 | |
|---|---|---|
Intent | Item reduction | Validation |
Time line | April 2010 - Sep 2010 | Dec 2010 - Feb 2011 |
Sociodemographic data (age, gender, ethnicity, education, marital and employment status) | ✓ | ✓ |
PMH instrument | 182 candidate item scale, 4 point Likert style response scale (1- not at all like me, 2 - some what like me, 3 - moderately like me, 4- very much like me) | 47-item scale, 6 point Likert style response scale (1- not at all like me, 2 - very slightly like me, 3 - slightly like me, 4- moderately like me, 5 - very much like me and 6- exactly like me) |
Other measures | General Health questionnaire | RSA |
EQ5D | MSPSS | |
General happiness item | Brief Cope | |
General health item | PGIS | |
DSES | ||
SWEMWBS | ||
SWLS | ||
General happiness item | ||
General health item | ||
EQ5D VAS | ||
Healthy days measure | ||
PHQ -8 | ||
GAD -7 | ||
SDS | ||
Analyses | Missing data, floor and ceiling effect | Missing data, floor and ceiling effect |
EFA, CFA | CFA | |
IRT-DIF | IRT-DIF | |
Internal consistency | Internal consistency, Criterion validity |