Table 2.

Methodological choices in the area of ‘work outcome domains and instruments’

Topics	Results from studies in inflammatory arthritis (n=58)		Aspects identified by authors of SLRs in other chronic diseases (n=24)
	n/N* (%)	Detailed information	n† (%)	Comments
5. Work outcome domains defined	52/58 (90%)	The work outcomes domain was defined in 51 studies—n/N* (%): Work status: 12/17 (71%)21 23 27 30 40 41 46 50 53 57 62 70 Sick leave: 46/46 (100%)16 18–22 24–27 29 31–39 42–47 49–56 58–60 63 65–69 71–73 Presenteeism: 39/40 (98%)17–21 24–26 28 31–39 42 43 48 50–56 58–64 67–69 71 73	13 (54%)	High variability in the definition of a work outcome in included studies precluding data pooling/meta-analysis97–99 102 105–107 109 111 113 114 117 120
6. Validated measurement of sick leave	42‡/46 (91%)	Of the studies that had sick leave as work outcome domain, 42 used validated instruments to assess it, n/N (%): WPAI: 29‡/46 (63%)18–21 24–26 31–34 36–39 42 43 50–53 55 56 58 63 67 69 71 73 WPS: 5‡/46 (11%)35 39 54 60 68 Workdays missed due to IA (long-term sick leave assessed in registries): 9/46 (20%)16 22 27 29 44–47 65	Not reported	–
7. Validated measurement of presenteeism	35‡/40 (88%)	Of the studies that had presenteeism as work outcome domain, 35 used validated and OMERACT endorsed instruments, n/N* (%): WPAI: 29‡/40 (73%)18–21 24–26 31–34 36–39 42 43 50–53 55 56 58 63 67 69 71 73 WLQ-25: 2/40 (5%)61 64 WPS: 5‡/40 (13%)35 39 54 60 68 WALS: 0/40 (0%) WAI: 0/40 (0%)	1 (4%) 1 (4%)	WPAI used only in a small number of studies119 Studies use qualitative, quantitative and economic non-standardised measures of work productivity119
8. Attribution of work participation to overall health	29/58 (50%)	The work outcome domain was assessed in relation to overall health (and not in relation to IA) in 46 studies, n/N* (%): Work status: 8/17 (47%)16 27 30 40 42 46 51 57 Sick leave: 23/46 (50%)16 18 20 22 25 27 29 31 33 34 38 42 44–47 49 51 55 58 65 67 72 Presenteeism: 15/40 (38%)17 18 20 25 31 33 34 38 42 51 55 58 61 64 67	Not reported	–
Topics	Results from studies in inflammatory arthritis (n=58)		Aspects identified by authors of SLRs in other chronic diseases (n=24)
	n/N* (%)	Detailed information		n/N* (%)
9. Recall period of self-reported sick leave and presenteeism	35/42 (82%)	The recall period of self-reported sick leave was ≤3 months in 34/37 (92%) studies (excluding registries as recall is not applicable)18–21 24–26 31–39 42 43 50–56 58–60 63 67–69 71 73 The recall period of self-reported presenteeism was of 7 days to 1 month in 34/40 (85%) studies18–21 24–26 31–39 42 43 50–56 58 60 62 63 67–69 71 73	1 (4%) 2 (8%)	Inconsistency of the recall period103 No accounting for a possible recall bias102 115

*The denominator may vary according to the corresponding assessed topic.

†Number of systematic literature reviews reporting on the corresponding topic.

‡Boer et al (2018) used both WPAI-RA and WPS-RA.

IA, inflammatory arthritis; n/N, number of original studies in which the methodological choice was identified/number of studies in which the topic was possible to assess; WALS, Workplace Activity Limitations Scale; WLQ-25, Work Limitations Questionnaire 25-item; WPAI, Work Productivity and Activity Impairment; WPS, Work Productivity Questionnaire.