Table 2.

Association between common infections and dementia overall and stratified by type of infection

	Total number of incident dementia diagnoses	Total person-years at risk	Crude incidence rate (95% CI)	Age-adjusted HR (95% CI)*	Age, sex, IMD, and calendar period adjusted HR (95% CI)†	Fully adjusted HR (95% CI)‡
No infection	25 314	3 895 032	6·50 (6·42–6·58)	1 (ref)	1 (ref)	1 (ref)
Any infection	31 488	1 754 956	17·94 (17·75–18·14)	1·78 (1·75–1·81)	1·64 (1·61–1·66)	1·53 (1·50–1·55)
Sepsis	427	16 814	25·40 (23·10–27·92)	2·48 (2·26–2·73)	2·18 (1·98–2·40)	2·08 (1·89–2·29)
Pneumonia	1247	47 836	26·07 (24·66–27·56)	2·27 (2·15–2·41)	1·98 (1·87–2·10)	1·88 (1·77–1·99)
Other LRTI	13 429	910 432	14·75 (14·50–15·00)	1·57 (1·54–1·60)	1·39 (1·36–1·42)	1·34 (1·31–1·37)
UTI	10 513	481 341	21·84 (21·43–22·26)	2·04 (1·99–2·08)	1·80 (1·75–1·84)	1·73 (1·69–1·78)
SSTI	5535	291 603	18·98 (18·49–19·49)	1·78 (1·73–1·83)	1·58 (1·53–1·62)	1·54 (1·49–1·58)

HR=hazard ratio. IMD=Index of multiple deprivation. LRTIs=lower respiratory tract infections (excluding pneumonia). UTIs=urinary tract infection. SSTI=skin and soft tissue infection.

^*Age as underlying timescale.

^†Adjusted for age, sex, patient level IMD, and calendar time period over follow-up (2004–08, 2009–13, and 2014–18).

^‡Adjusted for age, sex, patient level IMD, and calendar time period over follow-up (2004–08, 2009–13, and 2014–18), ethnicity, smoking status, heavy alcohol consumption, anxiety and depression, severe mental illness, inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, psoriasis, asthma, chronic kidney disease, chronic liver disease, chronic obstructive pulmonary disease, diabetes mellitus, heart failure, hypertension, obstructive sleep apnoea, stroke, traumatic brain injury, benzodiazepines, proton pump inhibitors, systemic corticosteroids, and polypharmacy.