Table 2.
Crude and adjusted associations between pertussis and occupational risk factors in adults and teenagers in England
| Risk factor group | Variable | Category | Univariable associations | Multivariable models | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M1 | M2A* | M2B† | M2C‡ | ||||||||||
| uOR (95% CI) | P | aOR (95% CI) | P | aOR (95% CI) | P | aOR (95% CI) | P | χ2 (P)§ | aOR (95% CI) | P | |||
| Demographics | Age quintiles | Q1: 15–32 years | 3·20 (1·82–5·95) | <0·001 | 3·56 (1·86–6·79) | <0·001 | 3·83 (1·93–7·61) | <0·001 | — | — | — | 3·83 (1·93–7·61) | <0·001 |
| Q2: 33–43 years | 2·83 (1·52–5·28) | 0·001 | 3·23 (1·68–6·22) | <0·001 | 3·35 (1·73–6·49) | <0·001 | — | — | — | 3·35 (1·73–6·49) | <0·001 | ||
| Q3: 44–51 years | 2·24 (1·22–4·13) | 0·010 | 2·38 (1·25–4·52) | 0·008 | 2·37 (1·22–4·60) | 0·011 | — | — | — | 2·37 (1·22–4·60) | 0·011 | ||
| Q4: 52–61 years | 1·42 (0·76–2·68) | 0·275 | 1·54 (0·80–2·98) | 0·204 | 1·48 (0·76–2·90) | 0·248 | — | — | — | 1·48 (0·76–2·90) | 0·248 | ||
| Q5: 62–87 years | Ref. | — | Ref. | — | Ref. | — | — | — | — | Ref. | — | ||
| Sex | Male | 1·73 (1·15–2·60) | 0·008 | 1·84 (1·19–2·83) | 0·006 | 1·86 (1·19–2·91) | 0·006 | — | — | — | 1·86 (1·19–2·91) | 0·006 | |
| Female | Ref. | — | Ref. | — | Ref. | — | — | — | — | Ref. | — | ||
| Region | London | 2·49 (1·00–6·22) | 0·051 | 1·98 (0·76–5·11) | 0·160 | 2·04 (0·78–5·34) | 0·145 | — | — | — | 2·04 (0·78–5·34) | 0·145 | |
| South West | 2·61 (1·24–5·48) | 0·011 | 3·14 (1·43–6·94) | 0·005 | 3·17 (1·43–7·04) | 0·005 | — | — | — | 3·17 (1·43–7·04) | 0·005 | ||
| West Midlands | 1·45 (0·93–2·27) | 0·102 | 1·42 (0·89–2·26) | 0·141 | 1·41 (0·88–2·25) | 0·154 | — | — | — | 1·41 (0·88–2·25) | 0·154 | ||
| Yorkshire & the Humber | Ref. | — | Ref. | — | Ref. | — | — | — | — | Ref. | — | ||
| Travel | Recent travel | Yes | 0·76 (0·50–1·17) | 0·222 | 0·67 (0·42–1·07) | 0·094 | 0·67 (0·41–1·07) | 0·091 | — | — | — | 0·67 (0·41–1·07) | 0·091 |
| Occupation | Social care | Yes | 1·85 (0·63–5·42) | 0·262 | — | — | 2·36 (0·75–7·39) | 0·141 | 2·46 (0·79–7·63) | 0·119 | 2·61 (0·106) | not included | — |
| Education | Yes | 0·99 (0·62–1·61) | 0·982 | — | — | 0·82 (0·49–1·42) | 0·485 | 0·80 (0·47–1·38) | 0·424 | 0·64 (0·424) | not included | — | |
| Health | Yes | 1·02 (0·55–1·88) | 0·948 | — | — | 0·59 (0·13–2·65) | 0·491 | 1·20 (0·62–2·34) | 0·591 | 0·29 (0·590) | not included | — | |
| Patient contact | Yes | 1·20 (0·62–2·35) | 0·589 | — | — | 2·18 (0·43–11·14) | 0·349 | 1·44 (0·69–2·99) | 0·328 | 0·97 (0·324) | not included | — | |
uOR, Unadjusted odds ratio; CI, confidence interval; aOR, adjusted odds ratio; Q1–Q5, quintiles 1–5; Ref., reference group.
Values in bold indicate statistical significance (P < 0·05).
*
All occupation variables added simultaneously to M1.
†
A separate model produced for each occupation variable added to M1.
‡
Variables added to M1 in order of increasing statistical significance according to P value from M2B, variables retained only if the lead to a statistically significant improvement in fit.
§
χ2 and associated P value of the likelihood ratio test of improved fit compared to M1.