Table 3.
Risk of Bell's palsy among participants in the nested case-control study
| Number of case patients (n=298) | Number of controls (n=1181) | Crude odds ratio (95% CI) | p value | Adjusted odds ratio (95% CI) | p value | ||
|---|---|---|---|---|---|---|---|
| Total | |||||||
| Not vaccinated | 256 (86%) | 1097 (93%) | 1 (ref) | .. | 1 (ref) | .. | |
| CoronaVac | 28 (9%) | 53 (4%) | 2·451 (1·477–4·067) | 0·0005 | 2·385 (1·415–4·022) | 0·0011 | |
| BNT162b2 | 14 (5%) | 31 (3%) | 2·062 (1·061–4·009) | 0·033 | 1·755 (0·886–3·477) | 0·11 | |
| Subgroup analysis | |||||||
| Male | |||||||
| Not vaccinated | 128 (81%) | 575 (92%) | 1 (ref) | .. | 1 (ref) | .. | |
| CoronaVac | 22 (14%) | 35 (6%) | 3·130 (1·698–5·770) | 0·0003 | 2·892 (1·541–5·426) | 0·0009 | |
| BNT162b2 | 8 (5%) | 17 (3%) | 2·194 (0·915–5·259) | 0·078 | 1·970 (0·820–4·734) | 0·13 | |
| Female | |||||||
| Not vaccinated | 128 (91%) | 522 (94%) | 1 (ref) | .. | 1 (ref) | .. | |
| CoronaVac | 6 (4%) | 18 (3%) | 1·411 (0·538–3·704) | 0·48 | 1·332 (0·496–3·574) | 0·57 | |
| BNT162b2 | 6 (4%) | 14 (3%) | 1·869 (0·674–5·180) | 0·23 | 1·772 (0·629–4·991) | 0·28 | |
| Age younger than 60 years | |||||||
| Not vaccinated | 125 (83%) | 540 (91%) | 1 (ref) | .. | 1 (ref) | .. | |
| CoronaVac | 15 (10%) | 28 (5%) | 2·563 (1·262–5·204) | 0·0092 | 2·618 (1·272–5·388) | 0·0090 | |
| BNT162b2 | 10 (7%) | 24 (4%) | 1·833 (0·850–3·953) | 0·12 | 1·696 (0·779–3·694) | 0·18 | |
| Age 60 years and older | |||||||
| Not vaccinated | 131 (89%) | 557 (95%) | 1 (ref) | .. | 1 (ref) | .. | |
| CoronaVac | 13 (9%) | 25 (4%) | 2·377 (1·145–4·933) | 0·020 | 2·362 (1·097–5·086) | 0·028 | |
| BNT162b2 | 4 (3%) | 7 (1%) | 3·053 (0·786–11·863) | 0·11 | 2·338 (0·515–10·611) | 0·27 | |
| Post-hoc analysis | |||||||
| Within 14 days between vaccination and diagnosis of Bell's palsy | |||||||
| Not vaccinated | 256 (93%) | 1023 (96%) | 1 (ref) | .. | 1 (ref) | .. | |
| CoronaVac | 14 (5%) | 20 (2%) | 3·354 (1·520–7·402) | 0·0027 | 3·264 (1·455–7·318) | 0·0041 | |
| BNT162b2 | 6 (2%) | 19 (2%) | 1·271 (0·495–3·260) | 0·62 | 1·071 (0·415–2·760) | 0·89 | |
| Longer than 14 days between vaccination and diagnosis of Bell's palsy | |||||||
| Not vaccinated | 256 (92%) | 1029 (97%) | 1 (ref) | .. | 1 (ref) | .. | |
| CoronaVac | 14 (5%) | 23 (2%) | 2·448 (1·231–4·868) | 0·011 | 2·320 (1·124–4·789) | 0·023 | |
| BNT162b2 | 8 (3%) | 9 (1%) | 3·943 (1·411–11·019) | 0·0089 | 3·778 (1·251–11·410) | 0·019 | |
| Completed first dose only | |||||||
| Not vaccinated | 256 (91%) | 1038 (96%) | 1 (ref) | .. | 1 (ref) | .. | |
| CoronaVac | 21 (7%) | 28 (3%) | 3·311 (1·772–6·185) | 0·0002 | 3·200 (1·679 ·6·099) | 0·0004 | |
| BNT162b2 | 5 (2%) | 18 (2%) | 1·093 (0·397–3·011) | 0·86 | 0·853 (0·290–2·507) | 0·77 | |
| Completed first and second dose | |||||||
| Not vaccinated | 256 (94%) | 1014 (97%) | 1 (ref) | .. | 1 (ref) | .. | |
| CoronaVac | 7 (3%) | 19 (2%) | 1·459 (0·592–3·599) | 0·41 | 1·453 (0·575–3·676) | 0·43 | |
| BNT162b2 | 9 (3%) | 12 (1%) | 3·201 (1·287–7·962) | 0·012 | 3·162 (1·245–8·036) | 0·016 | |
The list of confounders in the model for subgroup and post-hoc analyses is shown in appendix 2 (pp 17–18).