Table 3.

Association between common infections and dementia stratified by clinical setting

	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)‡
General practitioner recorded infections
No infection	37 298	4 115 228	9·06 (8·97–9·16)	1 (ref)	1 (ref)	1 (ref)
Any infection	24 314	1 554 615	15·64 (15·44–15·84)	1·20 (1·18–1·22)	1·09 (1·07–1·11)	1·02 (1·00–1·04)
Hospital recorded infections
No infection	51 127	5 534 732	9·24 (9·16–9·32)	1 (ref)	1 (ref)	1 (ref)
Any infection	7166	200 320	35·77 (34·95–36·61)	2·28 (2·22–2·34)	2·15 (2·10–2·20)	1·99 (1·94–2·04)
Hospital recorded infections (primary diagnosis)
No infection	57 142	5 641 094	10·13 (10·05–10·21)	1 (ref)	1 (ref)	1 (ref)
Any infection	3630	10 4147	34·85 (33·74–36·01)	2·10 (2·03–2·17)	1·99 (1·92–2·06)	1·84 (1·78–1·91)

HR=hazard ratio. IMD=Index of multiple deprivation.

^*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.