Test-retest reliability of candidate measures of at-work limitations/productivity (presenteeism).
| Instrument | Content Source | n (stable)* | Mean Baseline Score (SD) | Mean 2-wk Followup Score (SD) | ICC2,1 |
|---|---|---|---|---|---|
| Global measures | |||||
| WPS-RA (item 4)$ | Item 4 from the Rheumatoid Arthritis-Specific Work Productivity Survey | 35 | 3.7 (3.0) | 3.7 (3.4) | 0.87 |
| WPAI (item 5)$ | Item 5 from the Work Productivity and Activity Impairment Questionnaire (specific health problem version) | 34 | 3.9 (3.0) | 3.4 (2.9) | 0.84 |
| QQ method$ | Multiplication of 2 items (E1 and E2) from the Productivity and Disease Questionnaire (ProDISQ) | 33 | 61.2 (33.3) | 57.6 (34.2) | 0.77 |
| HPQ (item A12)$ | Item A12 from the Health and Work Performance Questionnaire | 36 | 7.1 (2.0) | 7.4 (2.1) | 0.83 |
| WAI (item 1) | Item 1 from the Work Ability Index | 6‡ | 7.5 (2.1) | 6.7 (2.5) | 0.80 |
| Multi-item measures | |||||
| WALS | Workplace Activity Limitations Scale (12 items) | 37 | 12.5 (7.3) | 12.2 (8.0) | 0.93 |
| WLQ-25 (adapted)†$ | Work Limitations Questionnaire-25 (4 subscales: TM: time management [5 items], PD: physical demands [6 items], MI: mental interpersonal [9 items], OD: output demands [5 items]); index score: weighted sum of subscales | 37 | TM = 36.5 (28.2); | TM = 34.2 (26.5); | TM = 0.93; |
| 37 | PD = 47.1 (32.9); | PD = 42.6 (32.9); | PD = 0.95; | ||
| 37 | MI = 25.6 (23.4); | MI = 27.0 (24.6); | MI = 0.79; | ||
| 34 | OD = 34.4 (28.9); | OD = 32.5 (31.6); | OD = 0.86; | ||
| 34 | Index = 9.6 (7.6) | Index = 9.3 (7.8) | Index = 0.93 |
↵* No change on an external anchor fielded at 2-wk followup (compared to when you completed the first questionnaire package, how would you rate your ability to do your usually work activities? 0 = much worse, 5 = no change, 10 = much better);
↵† WLQ-25 was modified in this study — instruction for the physical demands subscale was reoriented to be consistent with other subscales;
↵‡ low sample size because measure was introduced later in the survey.
↵$ instrument has potential for use in economic evaluations. ICC: intraclass correlation coefficients.