Associations between air pollution and mental health service use in dementia: A retrospective cohort study

TY - JOUR

T1 - Associations between air pollution and mental health service use in dementia: A retrospective cohort study

AU - Ronaldson, Amy

AU - Stewart, Robert

AU - Mueller, Christoph

AU - Das-Munshi, Jayati

AU - Newbury, Joanne

AU - Mudway, Ian

AU - Broadbent, Matthew

AU - Fisher, Helen

AU - Beevers, Sean

AU - Dajnak, David

AU - Hotopf, Matthew

AU - Hatch, Stephani

AU - Bakolis, Ioannis

N1 - Funding Information: AR is part supported by an MQ Fellows Award. HLF, JD-M and SH are part supported by the Economic and Social Research Council (ESRC) Centre for Society and Mental Health at King’s College London [ES/S012567/1]. IB, MH, JD-M and RS are part supported by the National Institute for Health and Care Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. RS is additionally part-supported by i) the NIHR Applied Research Collaboration South London (NIHR ARC South London) at King’s College Hospital NHS Foundation Trust; ii) UKRI – Medical Research Council through the DATAMIND HDR UK Mental Health Data Hub (MRC reference: MR/W014386); iii) the UK Prevention Research Partnership (Violence, Health and Society; MR-VO49879/1), an initiative funded by UK Research and Innovation Councils, the Department of Health and Social Care (England) and the UK devolved administrations, and leading health research charities. JD-M and IB are part supported by the NIHR Applied Research Collaboration South London (NIHR ARC South London) at King’s College Hospital NHS Foundation Trust. IM, DD and SB’s involvement was part funded by the NIHR Health Protection Research Unit in Environmental Exposures and Health, a partnership between The UK Health Security Agency (UKHSA) and Imperial College London. JBN is supported by a Sir Henry Wellcome Postdoctoral Fellowship from the Wellcome Trust (218632/Z/19/Z).AR is part supported by an MQ Fellows Award. HLF, JD-M and SH are part supported by the Economic and Social Research Council (ESRC) Centre for Society and Mental Health at King’s College London [ES/S012567/1]. IB, MH, JD-M and RS are part supported by the National Institute for Health and Care Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. RS is additionally part-supported by i) the NIHR Applied Research Collaboration South London (NIHR ARC South London) at King’s College Hospital NHS Foundation Trust; ii) UKRI – Medical Research Council through the DATAMIND HDR UK Mental Health Data Hub (MRC reference: MR/W014386); iii) the UK Prevention Research Partnership (Violence, Health and Society; MR-VO49879/1), an initiative funded by UK Research and Innovation Councils, the Department of Health and Social Care (England) and the UK devolved administrations, and leading health research charities. JD-M and IB are part supported by the NIHR Applied Research Collaboration South London (NIHR ARC South London) at King’s College Hospital NHS Foundation Trust. IM, DD and SB’s involvement was part funded by the NIHR Health Protection Research Unit in Environmental Exposures and Health, a partnership between The UK Health Security Agency (UKHSA) and Imperial College London. JBN is supported by a Sir Henry Wellcome Postdoctoral Fellowship from the Wellcome Trust (218632/Z/19/Z).AR is part supported by an MQ Fellows Award. HLF, JD-M and SH are part supported by the Economic and Social Research Council (ESRC) Centre for Society and Mental Health at King’s College London [ES/S012567/1]. IB, MH, JD-M and RS are part supported by the National Institute for Health and Care Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. RS is additionally part-supported by i) the NIHR Applied Research Collaboration South London (NIHR ARC South London) at King’s College Hospital NHS Foundation Trust; ii) UKRI – Medical Research Council through the DATAMIND HDR UK Mental Health Data Hub (MRC reference: MR/W014386); iii) the UK Prevention Research Partnership (Violence, Health and Society; MR-VO49879/1), an initiative funded by UK Research and Innovation Councils, the Department of Health and Social Care (England) and the UK devolved administrations, and leading health research charities. JD-M and IB are part supported by the NIHR Applied Research Collaboration South London (NIHR ARC South London) at King’s College Hospital NHS Foundation Trust. IM, DD and SB’s involvement was part funded by the NIHR Health Protection Research Unit in Environmental Exposures and Health, a partnership between The UK Health Security Agency (UKHSA) and Imperial College London. JBN is supported by a Sir Henry Wellcome Postdoctoral Fellowship from the Wellcome Trust (218632/Z/19/Z). Publisher Copyright: © 2023 Author(s). Published by BMJ.

PY - 2023/8/7

Y1 - 2023/8/7

N2 - BACKGROUND: Little is known about the role of air pollution in how people with dementia use mental health services. OBJECTIVE: We examined longitudinal associations between air pollution exposure and mental health service use in people with dementia. METHODS: In 5024 people aged 65 years or older with dementia in South London, high resolution estimates of nitrogen dioxide (NO2) and particulate matter (PM2.5 and PM10) levels in ambient air were linked to residential addresses. Associations between air pollution and Community Mental Health Team (CMHT) events (recorded over 9 years) were examined using negative binomial regression models. Cognitive function was measured using the Mini Mental State Examination (MMSE) and health and social functioning was measured using the Health of the Nation Outcomes Scale (HoNOS65+). Associations between air pollution and both MMSE and HoNOS65+ scores were assessed using linear regression models. FINDINGS: In the first year of follow-up, increased exposure to all air pollutants was associated with an increase in the use of CMHTs in a dose-response manner. These associations were strongest when we compared the highest air pollution quartile (quartile 4: Q4) with the lowest quartile (Q1) (eg, NO2: adjusted incidence rate ratio (aIRR) 1.27, 95% CI 1.11 to 1.45, p<0.001). Dose-response patterns between PM2.5 and CMHT events remained at 5 and 9 years. Associations were strongest for patients with vascular dementia. NO2 levels were linked with poor functional status, but not cognitive function. CONCLUSIONS: Residential air pollution exposure is associated with increased CMHT usage among people with dementia. CLINICAL IMPLICATIONS: Efforts to reduce pollutant exposures in urban settings might reduce the use of mental health services in people with dementia, freeing up resources in already considerably stretched psychiatric services.

AB - BACKGROUND: Little is known about the role of air pollution in how people with dementia use mental health services. OBJECTIVE: We examined longitudinal associations between air pollution exposure and mental health service use in people with dementia. METHODS: In 5024 people aged 65 years or older with dementia in South London, high resolution estimates of nitrogen dioxide (NO2) and particulate matter (PM2.5 and PM10) levels in ambient air were linked to residential addresses. Associations between air pollution and Community Mental Health Team (CMHT) events (recorded over 9 years) were examined using negative binomial regression models. Cognitive function was measured using the Mini Mental State Examination (MMSE) and health and social functioning was measured using the Health of the Nation Outcomes Scale (HoNOS65+). Associations between air pollution and both MMSE and HoNOS65+ scores were assessed using linear regression models. FINDINGS: In the first year of follow-up, increased exposure to all air pollutants was associated with an increase in the use of CMHTs in a dose-response manner. These associations were strongest when we compared the highest air pollution quartile (quartile 4: Q4) with the lowest quartile (Q1) (eg, NO2: adjusted incidence rate ratio (aIRR) 1.27, 95% CI 1.11 to 1.45, p<0.001). Dose-response patterns between PM2.5 and CMHT events remained at 5 and 9 years. Associations were strongest for patients with vascular dementia. NO2 levels were linked with poor functional status, but not cognitive function. CONCLUSIONS: Residential air pollution exposure is associated with increased CMHT usage among people with dementia. CLINICAL IMPLICATIONS: Efforts to reduce pollutant exposures in urban settings might reduce the use of mental health services in people with dementia, freeing up resources in already considerably stretched psychiatric services.

KW - Air pollution

KW - Particulate matter

KW - Nitrogen dioxide

KW - Dementia

KW - Health service use

KW - Alzheimer’s disease

UR - http://www.scopus.com/inward/record.url?scp=85166783854&partnerID=8YFLogxK

U2 - 10.1136/bmjment-2023-300762

DO - 10.1136/bmjment-2023-300762

M3 - Article

SN - 1362-0347

VL - 26

JO - Evidence-based mental health

JF - Evidence-based mental health

IS - 1

M1 - e300762

ER -