. 2023 Mar 16;23:260. doi: 10.1186/s12913-023-09240-x

Table 1.

Correlations at baseline, proportions (%) of selected variables and sample sizes of the intervention ( $N_{i}$ ) and control arm ( $N_{c}$ ). Cronbach’s $α$ of the scales (bold) on the diagonal of the correlation matrix. NA: Cronbach’s alpha not defined for the single items WAI-P and WAI-M

	WAI-P	WAI-M	Efforts	Low rewards	Overcommitment
WAI-P	NA
WAI-M	0.45	NA
Efforts	-0.44	-0.38	0.81
Low rewards	-0.29	-0.32	0.49	0.81
Overcommitment	-0.31	-0.44	0.57	0.41	0.80
Age (%)	18-39y: 23; 40-54y: 48, 55y and older: 29
Sex (%)	Male: 21, Female: 79
$N_{i}$	$t_{0}$ : 240, $t_{1}$ : 186, $t_{2}$ : 167
$N_{c}$	$t_{0}$ : 146, $t_{1}$ : 116, $t_{2}$ : 103
Attrition	from $t_{0}$ to $t_{1}$ : 22%, from $t_{0}$ to $t_{2}$ : 30%

WAI-P: physical work ability, WAI-M: mental work ability, NA: not available