Cross-sectional studyYuriko Suzuki, MD, MPH, PhDNational Institute of Mental Health, NCNPyrsuzuki@ncnp.go.jp

Key issuesWhy research? Descriptive study Hypothesis testing Association Sampling An example of cross-sectional study

Why research?To guide health practice and policy Because local research is often needed to guide local health practice and policy

Because carrying out research strengthens research capacity

What is a hypothesisA statement which describes what you expect to find in a specific mannerClearly statedTestable and refutableNot a mere research question or objectiveBacked by sample size calculation, and an appropriate design and analysis

ExampleStatement of the problem: mental health problems are said to be common in the aftermath of a disaster, and mental health problems are believed to be associated with physical damageAim: to describe the association between physical damage and mental health problemsQuestion: Are mental health problems associated with physical damage in time of disaster?Hypothesis: elderly people with poor mental health are more likely to have severe housing damage in time of disaster

Advantages of hypothesis-driven researchGreater credence given to validity of findings

Less risk of type I and II errorsType I error: mistakenly see association while there isnt.Type II error: mistakenly see no association while there is.

Ease of replication

What do epidemiologists do?DescribeDistribution of health-related states in a populationExtent, type, severityWho, where, when? ExplainAnalytical epidemiologyHypothesis-driven etiological researchRisk factors and causes EvaluateQuasi-experimental studiesRandomized controlled trials

Association Risk factorDiseaseExposureOutcomeIndependentDependentChanceBiasConfoundingTrue association?

Descriptive studiesCase series Cross-sectional studyMulti-center (geographic variance)Ecological correlation Repeated surveys (temporal variance)

Who to study?Population

SampleAdvantage: time and costDisadvantages: sampling error, bias if sample is not representative of population

Random samplingSimple Systematic Stratified Multi-stage and cluster

How big a sample?Sample size calculation is important to avoid errors in interpreting findings: Type I errors: The null hypothesis is rejected when it is in fact, true (p value)Type II errors:The null hypothesis is accepted when it is, in fact, false (power)

Prevalence studySuzuki Y, Tsutsumi A, Fukasawa M, et al. Prevalence of mental disorders and suicidal thoughts among community-dwelling elderly adults 3 years after the niigata-chuetsu earthquake. J Epidemiol. 21:144-50. 2011

*Niigata

Earthquakes in NiigataIn 2004: The Niigata- Chuetsu earthquake2004.10.23.5:56pmMagnitude:6.8 in Richter scaleSeismic intensity:7 in Japanese scaleDamage:68 deaths 4805 injuriesIn 2007: The Niigata Chuetsu-oki earthquake2007.7.16.10:13amMagnitude:6.8 in Richter scaleSeismic intensity:6 in Japanese scaleDamage:15 deaths 2345 injuries

Prevalence of mental health disorders among community dwelling elderly three year after the Niigata-Chuetsu earthquake Face-to-face interviews were conducted to the older people above 65 in the severely damaged area by the Niigata-Chuestu earthquake Diagnoses of mental disorder were confirmed using Mini International Neuropsychiatric Interview (M.I.N.I.), and quality of life (QOL) were measure by WHOQOL The prevalence and its associated factors were described.

*Data collection Trained health professionals administered the questionnaires and the following structures interviews; MeasurementDiagnosis of mental disorders (M.I.N.I.)Major depression (current, since the earthquake)Minor depression (current, since the earthquake) Suicidal tendency (current, since the earthquake)Posttraumatic stress disorder (current)Alcohol dependence and abuse (current)

QOLWHO/QOL-BREFPhysicalPsychologicalSocialEnvironmentalMethods

Unable to interviewAbsents(n=27)Due to disability (hearing, seeing, etc) (n=71)Refusal to interview (n=215)ResultsFlow of the study (2007.10.1-2008.1.11)

*Results2

Table 1. Characteristics of participants of the study of three year after the Niigata-Chuetsu earthquake in 2004 (n=473)n% Mean95% CIGenderMale19040.2 Age65-7420944.2 75+26455.8 Average age76.0 75.4-76.6Marital statusMarried32869.3 Divorced30.6 Bereaved14029.6 Never married20.4 EducationElementary school12827.5 Koutouka11224.0 Chugakko16735.8 Koukou204.3 OthersNumbers of yearin education8.2 8.1-8.4Number of cohabitant3.9 3.7-4.1Previous psychiatric visit194.3

Digit spam (3 digits)Incorrect2911.2

Severity of disaster damageResults3I. Prevalence study

Prevalence of mental disorders in 2 weeks and past 3 years among the older people living in community by gender (n=444)Results4****:p

(n=446) (n=443) (n=245)(n=445) (n=88) (n=51)Results5The percentage of those who met criterion A and B of PTSD in DSM-IV-TR by exposure of the earthquake and the other events

Results7QOL mean : male 3.54 (95%CI:3.47-3.60) female 3.48 (95%CI:3.43-3.53)

Results8

Results of regression analysis for quality of life and interviewees basic characteristics (n=439)VariablesPhysical PsychologicalSocialEnvironmentalMean QOL scoreCoef.Coef.Coef.Coef.Coef.Gender-0.05 -0.07 0.07 -0.10 *-0.05 (male=0, female=1)Age-0.01 0.00 0.00 0.00 0.00 yearMarital status0.03 0.01 -0.08 -0.04 0.00 (not married=0, married=1)Number of cohabitants0.02 0.03 *0.02 0.03 **0.03 *

Years in education-0.03 0.00 0.00 -0.01 -0.01

Previouspsychiatric visit-0.13 -0.03 -0.06 0.04 -0.03 (never=0, yes=1)Severity of disaster damage in 2004-0.05 *-0.03 -0.04 -0.03 -0.04 *

Physical illness-0.29 **-0.17 **-0.01 0.00 -0.15 **

Intercept4.9 3.6 4.1 3.6 3.9 Adjusted R20.060 0.022 0.003 0.015 0.034 *:p

Prevalence of major depression and PTSD was lower than previous researches in disaster settings in other countries6.4-11%, 4.4-25% respectively in literature.

The prevalence of major depression since the earthquake was 4.4%, within the range of the prevalence in non-disaster community studies (0.9-9.4% in literature).

Among males, the alcohol related problems were reported in 6.0% and among females, major or minor depression were reported in 10.0%, and suicidal tendency were seen in 8.0% of the interviewees.

Pathological levelabout same level as usualSubclinical level require further attention to promote their mental healthDiscussion1

In general, having fewer cohabitants, and greater degree of disaster damage, and any physical illness were attributing to the worse quality of life. The risk factors for poor QOL were severity of disaster damage, and physical illness in physical domain, fewer cohabitants and physical illness in psychological domain, being female, and fewer cohabitants in environmental domain. Mental health and physical health care would be better if provided hand in hand, and social support persistently had favorable effects on QOL among disaster affected elderly people. Discussion2

**Let me briefly mention two earthquakes in Niigata.Niigata experienced major earthquake twice three years in a row,In 2004, the Niigata-Chuetsu earthquake hit the mountainous area in mid Niigata.It caused 68 deaths.

In 2007, another earthquake hit the same area, with epicenter a little bit off toward the sea,This cause additional fear and uncertainty because the nuclear plant was also damaged by the earthquake.

*In our study, the aims are to know the prevalence of mental disorders,degree of subjective QOL, and to identify its risk factors three years after the Niigata-Chuetsu earthquake.To have better knowledge of vulnerable population in time of disaster, we targeted community-dwelling elderly people for this study.

*This is a cross-sectional study, and all interviewers had training for structured diagnostic interview.We used the MINI for diagnosis of mental disorders, specifically depression, suicidality, PTSD, and alcohol related problems.

QOL was measured using WHO/QOL-BREF, Japanese version, and the sub domains of physical, psychological, social and environmental aspects were evaluated.

This is the flow of the study participants.We identified 902 community dwelling older adults, 65 old and above,in three specific severely affected mountains area.With this breakdown of exclusion, we approached to 799 residents, resulting in 496 respondents, the completion rate was 62.1%.

*This is the demographics of participants.Number of cohabitants, I think this represent the characteristics of this community, many of them live with their family members.This area experienced the major earthquake twice, first one in 2004, and later, in 2007.In the first earthquake, more than half experienced half collapse of severer, which means they are qualified for relief grants.In the second earthquake, most of them did not have building damage.

*As for the point prevalence of three years after the Niigata-Chuetsu earthquakeRate of major was 0.6% in males and 0.8% in females, and rates including minor depression was 1.1 and 1.6%, respectively.No participants were found to meet the criteria for diagnosis of PTSD three years after the event. Experience of alcohol problems was reported only by males, 4.2% for alcohol dependence and 2.2% for alcohol abuse. 3.5% of males and 7.1% of females reported varying degrees of suicidal tendency.

In terms of rate during the three years after the earthquake, major depression was 1.7% in males, and 6.0% in females, and rates including minor depression was 4.7 in males and10.4% in females.More females tended to report suicidal tendency than males.*Although most of the participants (98.7%, n=440) experienced the earthquake, 46.5% reported intense fear, helplessness or horror to the event. Among those who experience and had fear to the event, only 4.5% reported that they re-experienced the event. *The mean score on the WHOQOL-BREF was 3.54 or males and 3.48 for females. In the sub-domains, no gender-based difference in mean score was found except for the environmental domain, where women scored significantly lower than men. In the graph, relatively poor psychological and environmental QOL were seen comparing to the social domain.*Finally we examined the risk factors of poor QOL as evaluated by the WHOQOL-BREF.In general, predicting mean QOL scores from the model, having more cohabitants worked protectively, while experience of a greater extent of disaster damage, and having physical illnesses were risks for lower QOL three years after the earthquake.

*Prevalence of major depression and PTSD was lower than previous researches in disaster settings in other countries6.4-11%, 4.4-25% respectively in literature.

The prevalence of major depression since the earthquake was 4.4%, within the range of the prevalence in non-disaster community studies (0.9-9.4% in literature).

Among males, the alcohol related problems were reported in 6.0% and among females, major or minor depression were reported in 10.0%, and suicidal tendency were seen in 8.1 % of the interviewees.

Pathological levelabout same level as usualSubclinical level require further attention to promote their mental health

Although the study area was severely affected area, however those who are vulnerable May have been hospitalized, or moved out of the area, and we could not reach to these people In this study. This year, we are conducting a study for these more vulnerable population.

*In general, having fewer cohabitants, and greater degree of disaster damage, and any physical illness were attributing to the worse quality of life. Mental health and physical health care would be better if provided hand in hand, and social support persistently had favorable effects on QOL among disaster affected elderly people.

*