The English National Cohort Study of Flooding & Health: psychological morbidity at three years of follow up.

BACKGROUND: Flooding is expected to increase due to climate change, population growth and urban development. The longer-term mental health impacts of flooding are not well understood. In 2015, the English National Study of Flooding and Health was established to improve understanding of the impact of flooding on health and inform future public health action. METHODS: We used 3 years of data from the English National Study of Flooding and Health. Participants who had consented to follow up were sent a questionnaire. Participants were classified into either "unaffected", "disrupted" or "flooded" according to their exposure. Logistic regression models were used to calculate adjusted odds ratios for probable depression, anxiety and post-traumatic stress disorder (PTSD) in each exposure group. The Wald test was used to assess the difference in probable mental health outcomes for those who did and did not experience "persistent damage" to their home. Conditional logistic regression was conducted to assess change in prevalence over the 3 years and to identify possible determinants of recovery. RESULTS: Eight hundred nineteen individuals were included in the final analysis - 119 were classified as unaffected, 421 disrupted and 279 flooded. Overall, 5.7% had probable depression, 8.1% had probable anxiety and 11.8% had probable PTSD, with higher prevalence in the flooded group compared with the unaffected group. After adjustment for potential confounders, probable mental health outcomes were higher in the flooded group compared to the unaffected group, significantly for probable depression (aOR 8.48, 95% CI 1.04-68.97) and PTSD (aOR 7.74, 95% CI 2.24-26.79). Seventy-seven (9.4%) participants reported experiencing persistent damage to their home, most commonly damp (n = 40) and visible mould (n = 26) in liveable rooms. Of the 569 participants who responded at all 3 years, a significant reduction in prevalence for all probable mental health outcomes was observed in the flooded group. CONCLUSIONS: Flooding can have severe long-lasting consequences on mental health in affected populations. If these problems are not identified and treated early, they may persist for years. Further research is necessary to develop and evaluate interventions to increase resilience in at risk populations and to ensure timely access to support services following flooding.

Impact of flooding on health-related quality of life in England: results from the National Study of Flooding and Health.

BACKGROUND: Flooding can have extensive effects on the health and wellbeing of affected communities. The impact of flooding on psychological morbidity has been established; however, the wider impacts of flooding exposure, including on health-related quality of life (HRQoL), have not been described. METHODS: Using data from the English National Study of Flooding and Health cohort, HRQoL 2 and 3 years post-flooding was assessed with the EuroQol Group EQ-5D-5L tool. Associations between exposure groups (flooding and disruption from flooding) and HRQoL were assessed, using ordinal and linear regression, adjusting for a priori confounders. RESULTS: For both 2 and 3 years post-flooding, the median HRQoL scores were lower in the flooded and disrupted groups, compared with unaffected respondents. A higher proportion of flooded and disrupted respondents reported HRQoL problems in most dimensions of the EQ-5D-5L, compared with unaffected respondents. In year 2, independent associations between exposure to flooding and experiencing anxiety/depression [adjusted odds ratio (aOR) 7.7; 95% CI 4.6-13.5], problems with usual activities (aOR 5.3; 95% CI 2.5-11.9) and pain/discomfort (aOR 2.4; 95% CI 1.5-3.9) were identified. These problems persisted 3 years post-flooding; associations between exposure to flooding and experiencing anxiety/depression (aOR 4.3; 95% CI 2.5-7.7), problems with usual activities (aOR 2.9; 95% CI 1.5-6.1) and pain/discomfort (aOR 2.5; 95% CI 1.5-4.2) were identified. CONCLUSIONS: Exposure to flooding and disruption from flooding significantly reduces HRQoL. These findings extend our knowledge of the impacts of flooding on health, with implications for multi-agency emergency response and recovery plans.

The English National Cohort Study of Flooding and Health: the change in the prevalence of psychological morbidity at year two.

BACKGROUND: The longer term impact of flooding on health is poorly understood. In 2015, following widespread flooding in the UK during winter 2013/14, Public Health England launched the English National Study of Flooding and Health. The study identified a higher prevalence of probable psychological morbidity one year after exposure to flooding. We now report findings after two years. METHODS: In year two (2016), a self-assessment questionnaire including flooding-related exposures and validated instruments to screen for probable anxiety, depression and post-traumatic stress disorder (PTSD) was sent to all participants who consented to further follow-up. Participants exposure status was categorised according to responses in year one; we assessed for exposure to new episodes of flooding and continuing flood-related problems in respondents homes. We calculated the prevalence and odds ratio for each outcome by exposure group relative to unaffected participants, adjusting for confounders. We used the McNemar test to assess change in outcomes between year one and year two. RESULTS: In year two, 1064 (70%) people responded. The prevalence of probable psychological morbidity remained elevated amongst flooded participants [n = 339] (depression 10.6%, anxiety 13.6%, PTSD 24.5%) and disrupted participants [n = 512] (depression 4.1%, anxiety 6.4%, PTSD 8.9%), although these rates were reduced compared to year one. A greater reduction in anxiety 7.6% (95% confidence interval [CI] 4.6-9.9) was seen than depression 3.8% (95% CI 1.5-6.1) and PTSD: 6.6% (95% CI 3.9-9.2). Exposure to flooding was associated with a higher odds of anxiety (adjusted odds ratio [aOR] 5.2 95%, 95% CI 1.7-16.3) and depression (aOR 8.7, 95% CI 1.9-39.8) but not PTSD. Exposure to disruption caused by flooding was not significantly associated with probable psychological morbidity. Persistent damage in the home as a consequence of the original flooding event was reported by 119 participants (14%). The odds of probable psychological morbidity amongst flooded participants who reported persistent damage, compared with those who were unaffected, were significantly higher than the same comparison amongst flooded participants who did not report persistent damage. CONCLUSIONS: This study shows a continuance of probable psychological morbidity at least two years following exposure to flooding. Commissioners and providers of health and social care services should be aware that the increased need in populations may be prolonged. Efforts to resolve persistent damage to homes may reduce the risk of probable psychological morbidity.

The English national cohort study of flooding and health: cross-sectional analysis of mental health outcomes at year one.

BACKGROUND: In winter 2013/14 there was widespread flooding in England. Previous studies have described an increased prevalence of psychological morbidity six months after flooding. Disruption to essential services may increase morbidity however there have been no studies examining whether those experiencing disruption but not directly flooded are affected. The National Study of Flooding and Health was established in order to investigate the longer-term impact of flooding and related disruptions on mental health and wellbeing. METHODS: In year one we conducted a cross sectional analysis of people living in neighbourhoods affected by flooding between 1 December 2013 and 31 March 2014. 8761 households were invited to participate. Participants were categorised according to exposure as flooded, disrupted by flooding or unaffected. We used validated instruments to screen for probable psychological morbidity, the Patient Health Questionnaire (PHQ 2), Generalised Anxiety Disorder scale (GAD-2) and Post Traumatic Stress Disorder (PTSD) checklist (PCL-6). We calculated prevalence and odds ratios for each outcome by exposure group relative to unaffected participants, adjusting for confounders. RESULTS: 2126 people (23%) responded. The prevalence of psychological morbidity was elevated amongst flooded participants ([n = 622] depression 20.1%, anxiety 28.3%, PTSD 36.2%) and disrupted participants ([n = 1099] depression 9.6%, anxiety 10.7% PTSD 15.2%). Flooding was associated with higher odds of all outcomes (adjusted odds ratios (aORs), 95% CIs for depression 5.91 (3.91-10.99), anxiety 6.50 (3.77-11.24), PTSD 7.19 (4.33-11.93)). Flooded participants who reported domestic utilities disruption had higher odds of all outcomes than other flooded participants, (aORs, depression 6.19 (3.30-11.59), anxiety 6.64 (3.84-11.48), PTSD 7.27 (4.39-12.03) aORs without such disruption, depression, 3.14 (1.17-8.39), anxiety 3.45 (1.45-8.22), PTSD 2.90 (1.25-6.73)). Increased floodwater depth was significantly associated with higher odds of each outcome. Disruption without flooding was associated with borderline higher odds of anxiety (aOR 1.61 (0.94-2.77)) and higher odds of PTSD 2.06 (1.27-3.35)) compared with unaffected participants. Disruption to health/social care and work/education was also associated with higher odds of psychological morbidity. CONCLUSIONS: This study provides an insight into the impact of flooding on mental health, suggesting that the impacts of flooding are large, prolonged and extend beyond just those whose homes are flooded.

Effect of evacuation and displacement on the association between flooding and mental health outcomes: a cross-sectional analysis of UK survey data.

BACKGROUND: Extensive flooding occurred during the winter of 2013-14 in England. Previous studies have shown that flooding affects mental health. Using data from the 2013-14 Public Health England National Study of Flooding and Health, we compared the prevalence of symptoms of depression, anxiety, and post-traumatic stress disorder between participants displaced by flooding and those flooded, but not displaced, 1 year after flooding. METHODS: In this multivariable ordinal regression analysis, we collected data from a cross-sectional survey collected 1 year after the flooding event from flood-affected postcodes in five counties in England. The analysis was restricted to individuals whose homes were flooded (n=622) to analyse displacement due to flooding. The primary outcome measures were depression (measured by the PHQ-2 depression scale) and anxiety (measured by the two-item Generalised Anxiety Disorder [GAD]-2 anxiety scale), and post-traumatic stress disorder (measured by the Post-Traumatic Stress Disorder Checklist [PCL]-6 scale). We adjusted analyses for recorded potential confounders. We also analysed duration of displacement and amount of warning received. FINDINGS: People who were displaced from their homes were significantly more likely to have higher scores on each scale; odds ratio (OR) for depression 1·95 (95% CI 1·30-2·93), for anxiety 1·66 (1·12-2·46), and for post-traumatic stress disorder 1·70 (1·17-2·48) than people who were not displaced. The increased risk of depression was significant even after adjustment for severity of flooding. Scores for depression and post-traumatic stress disorder were higher in people who were displaced and reported receiving no warning than those who had received a warning more than 12 h in advance of flooding (p=0·04 for depression, p=0·01 for post-traumatic stress disorder), although the difference in anxiety scores was not significant. INTERPRETATION: Displacement after flooding was associated with higher reported symptoms of depression, anxiety, and post-traumatic stress disorder 1 year after flooding. The amount of warning received showed evidence of being protective against symptoms of the three mental illnesses studied, and the severity of flooding might be the reason for some, but not all, of the differences between the groups. FUNDING: National Institute for Health Research Health Protection Research Units (HPRU) in Emergency Preparedness and Response at King's College London, Environmental Change and Health at the London School of Hygiene and Tropical Medicine, and Evaluation of Interventions at the University of Bristol, Public Health England.