Table 1 Presenting baseline characteristics of the cohort with baseline stable NCP or CRP and individuals excluded from the study due to reporting CWP in − 95 and/or − 98. Prevalence of baseline exposures and covariates in included and excluded subjects, and history of CWP in excluded individuals. Significance of differences between included and excluded subjects are presented as p-values (tested with t-test and chi2-test respectively)
Included cohort (stable NCP or CRP) (n = 1512) | Excluded subjects (CWP in 1995 and/or 1998) (n = 340) | p-value for diff. Incl. vs excl. | |
|---|---|---|---|
Age (1998) | < 0.01 | ||
Mean (sd) | 49 (15) | 56 (13) | |
Gender; n (%) | <.01 | ||
Male | 729 (48) | 111 (33) | |
Female | 783 (52) | 229 (67) | |
Initiating sleep; n (%) | <.01 | ||
No Problem | 1211 (81) | 175 (53) | |
Problem | 282 (19) | 158 (47) | |
Maintaining sleep; n (%) | <.01 | ||
No Problem | 1024 (69) | 109 (33) | |
Problem | 461 (31) | 220 (67) | |
Early awakening; n (%) | <.01 | ||
No Problem | 1149 (78) | 145 (44) | |
Problem | 331 (22) | 186 (56) | |
Non restorative sleep; n (%) | <.01 | ||
No Problem | 1075 (73) | 123 (37) | |
Problem | 404 (27) | 207 (63) | |
Fatiguea | <.01 | ||
Mean (sd) | 72 (21) | 44 (25) | |
Number of Regions | <.01 | ||
0 | 1096 (73) | 42 (12) | |
1–2 | 204 (13) | 10 (3) | |
3–5 | 177 (12) | 80 (24) | |
6–11 | 35 (2) | 152 (45) | |
12–18 | 0 | 56 (17) | |
Mental Healthb | < .01 | ||
Mean (sd) | 84 (17) | 69 (23) | |
Socio economyc | < .01 | ||
High non manual work | 440 (29) | 48 (14) | |
Ass non manual | 212 (14) | 55 (16) | |
Manual | 664 (44) | 196 (58) | |
Others | 196 (13) | 41 (13) | |
CWP history at baseline | |||
CWP in −95 only | – | 103 (30) | |
CWP in −98 only | – | 101 (30) | |
CWP in both −95 and − 98 | – | 136 (40) | |