Table 5.
Results of the univariable and multivariable analyses of factors (listed as variables) that could influence mumps outbreaks
| Variable (obs) | Level | Outbreak* | Univariable analysis | Multivariable analysis | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| No | Yes | % outbreak | OR | (95% CI) | P value | OR | (95% CI) | P value | ||
| Age group | <5 yr | 2 | 15 | 88·2 | 1·00 | Baseline | 1·00 | Baseline | ||
| 5–9 yr | 2 | 15 | 88·2 | 1·00 | (0·12–8·06) | 1·64 | (0·10–26·56) | |||
| 10–14 yr | 3 | 14 | 82·4 | 0·62 | (0·09–4·29) | 0·30 | (0·03–3·48) | |||
| 15–19 yr | 3 | 14 | 82·4 | 0·62 | (0·09–4·29) | 0·40 | (0·03–5·46) | |||
| (n = 85) | ⩾20 yr | 7 | 10 | 58·8 | 0·19 | (0·03–1·11) | 0·254 | 0·34 | (0·04–2·53) | 0·591 |
| Seroprevalence (80) | <80% | 3 | 44 | 93·6 | 1·00 | Baseline | ||||
| ⩾80% | 12 | 21 | 63·6 | 0·12 | (0·03–0·47) | 0·001 | ||||
| MMR1 | <90% | 0 | 16 | 100·0 | 1·00 | Baseline | 1·00 | Baseline | ||
| 90–95% | 0 | 17 | 100·0 | 1·00 | (0.00–inf.) | 3·82 | n.e. | |||
| (n = 75) | >95% | 15 | 27 | 64·3 | 0·00 | (0.00–inf.) | <0·001 | 0·00 | (0.00–inf.) | <0·001 |
| Years between doses | <4 yr | 2 | 28 | 93·3 | 1·00 | Baseline | 1·00 | Baseline | ||
| 4–8 yr | 10 | 20 | 66·7 | 0·14 | (0·03–0·72) | 0·08 | (0·01–0·85) | |||
| (n = 85) | >8 yr | 5 | 20 | 80·0 | 0·29 | (0·05–1·62) | 0·033 | 0·26 | (0·02–2·98) | 0·040 |
| Rubini strain | Other | 16 | 64 | 80·0 | 1·00 | Baseline | 1·00 | Baseline | ||
| (n = 85) | Rubini | 1 | 4 | 80·0 | 1·00 | (0·10–9·57) | 1·000 | 0·13 | (0·00–3·93) | 0·249 |
OR, Odds ratio; CI, confidence interval; n.e., not possible to estimate.
*
Defined by incidence with 1/100 000 cut-off.