A Study On The Relationship Between Temperature Change And Schizophrenia Onset In Hefei Area

Objective: 1.To understand the distribution characteristic of schizophrenia onset in Hefei from 2005 to 2014;2.Use the method of distributed lag non-linear model(DLNM)to analyze the relationship between mean temperature and schizophrenia onset,and explore potential vulnerable people;3.Investigate whether temperature variation(diurnal temperature range(DTR)and temperature change between neighboring days(TCN))could affect schizophrenia onset.Method: Daily meteorological data including maximum temperature,mean temperature,minimum temperature,relative humidity and rainfall were collected from January 1,2005 to December 31,2014.During the same periods,daily counts of schizophrenia emergency presentations were requested from Anhui Mental Health Center.All cases were hospitalized for acute onset of schizophrenia,which included date of admission,age,gender,residential address,marital status and season of birth.A Poisson generalized linear regression combined with DLNM was applied to analyze the association between temperature change(including mean temperature,DTR and TCN)and schizophrenia onset,after adjusting for long-term and seasonal trends,day of week and other confounding factors.Results:(1)During the study period(2005-2014),a total of 36607 emergency hospital admissions for schizophrenia were included in our analyses.There was a marked difference in age distribution,with more patients aged 21-40 years(19127 cases,52.2%).More cases in married patients than unmarried patients were observed,the ratio was 2.7:1(26249:9809).The daily mean admissions for schizophrenia were significantly higher in patients born in winter than in those born in other seasons.(2)When mean temperature reach at 24.9°C(P75),temperature could significantly influence the risk of schizophrenia onset,and revealed a delayed effect for high temperature.Of which,the cumulative effect for high temperature at lag 0-7 was1.27%(95%CI: 1.14-1.42).After stratifying by gender,age,marital status and season of birth,we found male patients,patients aged 21-60 years,married patients and patients born in spring/winter were more sensitive to the temperature increase.(3)Extremely high DTR(P95)was significantly associated with schizophrenia onset,and DTR effect appeared to be acute and decreased to lag 6 days.When stratified by individual characteristics,we observed that DTR exposure exhibited greater effects on males,patients aged ≧21 years,patients born in spring/autumn and married patients than other groups,respectively.Meanwhile,the risk for schizophrenia onset due to large DTR exposure increased from the first five years(2005-2009)to the second five years(2010-2014).However,there was no significant association between moderately high DTR(75th percentile)and schizophrenia onset.(4)Large temperature change between neighboring days(P75: 1.4°C)could increase the risk of schizophrenia onset,specially for exposure at current day(RR=1.9%,95%CI: 0.4%-3.4%).Also,we found vulnerable people who were patients aged 21-40 years,married patients and patients born in spring/autumn.Conclusion: Both temperature increase and temperature variation in short-term could significantly increase the risk of schizophrenia onset,and its adverse effects were modified by individual characteristics.Overall,males,patients aged 21-40 years and patients born in spring were more likely to be influenced by temperature change.