Presentation on theme: "ENVIRONMENTAL EPIDEMIOLOGY OF PSYCHOSES: Lessons from Nottingham Jouko Miettunen Department of Public Health and Primary Care Institute of Public Health."— Presentation transcript:
ENVIRONMENTAL EPIDEMIOLOGY OF PSYCHOSES: Lessons from Nottingham Jouko Miettunen Department of Public Health and Primary Care Institute of Public Health University of Cambridge June 17th, 2003
PSYCHOTIC DISORDERS §chronic, severe, and disabling brain diseases §life-time prevalence approximately l 1% in schizophrenia l 1% other psychoses §more common in urban than in rural areas §more common in western countries
POSSIBLE ENVIRONMENTAL RISK FACTORS §related to urban birth or to upbringing §population density §stressful life-events §air pollution §social deprivation §temporal order can be the opposite l social drift? l more healthy people may move out from deprived areas?
Nottingham Health Authority Area §about 600,000 people in 105 electoral wards §districts of Nottingham, Ruschliffe, Broxtowe, Gedling and Ashfield §several previous studies (1969-1988) on schizophrenia and other psychoses l possible to estimate trends in incidence §relatively high social deprivation and incidence of schizophrenia
SAMPLES OF THE STUDY §SIN DATA l “Schizophrenia Incidence in Nottingham” l all incidence cases of psychoses in Nottingham Health Authority Area 1.6.1992 - 31.5.1994 l 167 cases (166 with known address) §ÆSOP DATA l “Aetiology and Ethnicity in Schizophrenia and Other Psychoses” l three-centre study (other centres are Bristol and South London) l all incidence cases of psychoses in Nottingham Health Authority Area 1.8.1997 - 31.7.1999 l 206 cases (202 with known address)
INDIVIDUAL VARIABLES DISTRIBUTIONS 1992-94 (N=167) 1997-99 (N=206) §Gender: males 98 (59%) 123 (60%) §Median age 28 y 30 y §Diagnoses l Narrow schizophrenia 56 67 l Broad schizophrenia 82 116 l Affective psychosis 85 90 §Ethnic groups l White 122 (73%) 159 (77%) l African-Caribbean 26 (16%) 26 (13%) l Other 19 (11%) 21 (10%)
POPULATION DATA §Census 1991 population of Nottingham l population at risk (16 to 64 years): 389,389 l after under-enumeration corrections: 399,439 §till 1992-94 population has increased approximately 2% and till 1997-99 approximately 6% from this estimate
ELECTORAL WARD LEVEL VARIABLES §Multiple Deprivation Index 2000 l Income l Employment l Housing l Health deprivation and disability l Education, skills and training l Geographical access to services §population density §proportion of ethnic minorities
HYPOTHESES OF THE STUDY §Incidence of psychoses is higher in more deprived areas (and/or in areas with higher population density) §Incidence of psychoses among ethnic minorities is relatively higher in areas with lower proportion of ethnic minorities l lack of social support?
ANNUAL INCIDENCE OF ALL PSYCHOSES BY SOCIAL DEPRIVATION NOTTINGHAM 1992-1994 34 24 170 77 18 14 160 71 18 15 222 53 12 11 272 0 0 50 100 150 200 250 300 ALLwhiteafro-c.others I (high) IV(low) II III
39 29 204 64 19 16 128 53 22 20 167 70 20 18 136 69 0 50 100 150 200 250 ALLwhiteafro-c.others ANNUAL INCIDENCE OF ALL PSYCHOSES BY SOCIAL DEPRIVATION NOTTINGHAM 1997-1999 I (high) II III IV (low)
PLAN FOR ANALYSES §Age-standardised rates (Nottingham as a standard) §Two studies separately and pooled §Results by §Sex §Ethnic group §Subdiagnoses §narrow schz, broad schz and affective psychosis §each of the six variables in the deprivation score §Poisson regression analyses
LIMITATIONS §Electoral ward as a unit? §Case-ascertainment? §Census population? §Social deprivation scores? l analyses can be repeated with other scores §Causality?
FUTURE WORK (1) §Smaller units than electoral wards l enumeration districts (no information on ethnicity) l using e.g. principal component analysis §Census 2001 variables are soon available l update all the analyses with new population data l update all the the analyses with new social deprivation variables l combinations of census 1991 and 2001 variables
FUTURE WORK (2) §Case-control study of ÆSOP l multilevel analyses with individual level variables e.g. social class §ÆSOP is a three-centre study l replicate the analyses in Bristol and South London
CONCLUSIONS §Preliminary findings: l incidence of schizophrenia is about 1.5 more common in the most deprived areas
CONCLUSIONS §Preliminary findings: l incidence of schizophrenia is about 1.5 more common in the most deprived areas §Much more work is needed in this thesis and also elsewhere to study social deprivation and incidence of psychoses §All your comments will be very helpful Thank You!