Zero-inflated part (ZI) | Negative binomial part (NB) | |||
Coefficient | OR (95 CI) | Coefficient | MR (95 CI) | |
Baseline (odds for ZI, mean for NB) | 0.29 | 0.75 (0.41 to 1.37) | 1.60 | 4.93 (3.45 to 7.04) |
Male blue collar | 1.99 | 7.30 (4.72 to 11.30) | 0.67 | 1.95 (1.45 to 2.62) |
Male white collar (ref) | 0 | 1 | 0 | 1 |
Female white collar | 1.42 | 4.13 (2.20 to 7.76) | 0.02 | 1.02 (0.68 to 1.54) |
Age (years) | ||||
1829 | 0.16 | 1.17 (0.48 to 2.86) | 0.05 | 1.05 (0.72 to 1.52) |
3034 | 0.21 | 1.24 (0.52 to 2.93) | 0.04 | 0.96 (0.65 to 1.40) |
3539 (ref) | 0 | 1 | 0 | 1 |
4044 | 0.22 | 0.81 (0.40 to 1.63) | 0.15 | 0.86 (0.62 to 1.20) |
4549 | 0.68 | 0.51 (0.26 to 1.01) | 0.01 | 1.01 (0.71 to 1.43) |
5054 | 0.64 | 0.53 (0.26 to 1.06) | 0.09 | 0.91 (0.65 to 1.27) |
5561 | 0.68 | 0.51 (0.26 to 1.01) | 0.16 | 1.18 (0.84 to 1.66) |
Health problems | ||||
None (ref) | 0 | 1 | 0 | 1 |
One | 0.24 | 1.27 (0.76 to 2.12) | 0.62 | 1.87 (1.44 to 2.42) |
Two or more | 0.92 | 2.51 (1.35 to 4.68) | 1.23 | 3.41 (2.64 to 4.40) |
Estimated model coefficients, odds ratios (OR) and mean ratios (MR) with 95 CI from fitting a zero-inflated negative binomial regression Model 1 including age, gender, occupational grade and the presence of self-reported health problems as covariates.
The estimate of the dispersion parameter was 0.56.
Zero-inflated part refers to the model component for predicting membership to the subpopulation A with high propensity to zero absence, and Negative binomial part to the component predicting the days on sick leave among the susceptible subpopulation B. To facilitate interpretation, for the zero-inflation part we have shown the odds ratios associated with the complementary propensity to having any sickness absencethat is, inclusion in subpopulation B.