Public Health (1990), 104, 65-71
© The Societyof Public Health, 1990
Inequalities in Health" Socioeconomic Differences in Self-Reported Morbidity P. Y u e n 1, D. M a c h i n 1"2 and R. Balarajan 1
1Epidemiology and Public Health Research Unit, University of Surrey, Gui/dford, Surrey GU2 5XH; 2Medical Research Council, Cancer Trials Office, Shaftsbury Road, Cambridge CB2 2BW
Socioeconomic differences in self-reported chronic and acute illness were investigated in men and women using data from the General Household Surveys (1981-4). Logit models were used to investigate the influence of age, socioeconomic group, tenure, access to cars, area of residence and marital status on these measures of morbidity. For both measures local authority tenants, whether male or female, reported the most morbidity as did those with no access to cars. Both males and females reported increasing levels of illness the lower their socioeconomic group but similar patterns were not observed with acute illness. The significance of these present day inequalities is discussed.
Introduction Publication of the Registrar General's latest decennial supplement on occupational mortality I provided the most recent evidence on inequalities in health as measured by mortality differences across social class groups. Examination o f the data for successive decennial supplements showed evidence o f the widening of such inequalities nationally, over the past d e c a d e Y Regional differences in inequalities have also been demonstrated using the latest decennial supplement 4 and there is further evidence for the widening o f such inequalities in some Health Regions. 5 A p a r t from the Registrar General's social class, 6 other socioeconomic variables such as housing tenure, access to cars, have been shown to have independent contributions to mortality levels. 7 In this study we have examined inequalities in health in terms o f morbidity across a r a n g e o f social variables for the period roughly corresponding to the latest decennial supplement using the General Household Surveys o f 1981-4. 8-H
Materials and methods The General Household Survey (GHS) is an annual sample survey o f the population resident in private households in Great Britain, conducted by the Office o f Population Censuses and Surveys. D a t a are available on some 30,000 individuals aged 16 and above, on a wide range o f social variables including socioeconomic groups, marital status, access to cars, housing, employment, area o f residence and health. The socioeconomic status of married women is recorded as that o f their present or last jobs. A m o n g the questions on health the G H S elicit information on chronic illness and on acute illness. Acute illness is defined as that which causes restriction o f activity in the 14 days preceding the interview.
66
P. Yuen et al.
The question on chronic illness asks the individuals whether they have any long-standing illness, disability or infirmity. D a t a relating to the surveys 1981-4 were used for this analysis. The years 1981-2 and 1983-4 were pooled separately to obtain sufficient numbers in cells in the corresponding cross-tabulations but yet enable examination o f possible changes with time. We confined our attention to responses concerning those less than 65 as a relatively large p r o p o r t i o n of those over this age are in specialised residential accommodation which is not sampled by the G H S . Preliminary analysis suggested that the six abbreviated socioeconomic groups used by the G H S could be further regrouped into four relatively homogeneous categories. We term these upper, intermediate, junior non-manual, skilled m a n u a l and lower socioeconomic groups. The urban/rural classification was not available for the 1984 data. For each sex the probability of a health outcome (episodes of chronic and acute illness separately) was modelled with respect to age, socioeconomic group, tenure (local authority tenant or owner occupier), access to cars, area o f residence (urban or rural) and marital status by means o f logistic regression. A null model would correspond to the situation in which none o f the variables under study appears to influence the probability o f a particular health outcome. The models considered, first included all main effects and associated interaction terms and then a selection procedure was adopted to choose a reduced model in which only the important variables and interactions with respect to the particular health outcome were included. Once a satisfactory model was chosen estimates o f odds ratios (OR) and corresponding 95 % confidence intervals were calculated. A measure of goodness o f fit of the model is provided by the deviance which is distributed approximately as a chi-squared distribution with the appropriate degrees of freedom. In the event it turned out that for all situations considered here a model, including main effects only, explained a substantial proportion o f the variation. The statistical package G L I M l: was used to fit the models, for completeness non-significant main effect terms are also summarised in the results section. Results
Chronic illness (males) The O R ' s for the various at risk groups derived f r o m the main effects model for self-reported chronic illness in the males are summarised in Table I. There was an increase in reported morbidity with lowering of socioeconomic group and excess reporting amongst council tenants and those without access to cars. There was a general increase in reporting with age. A close correspondence between the O R ' s for each risk group was evident for each two-year interval. The highest reporting group were the 55-64-year-old council tenants o f lower socioeconomic group, with no access to car O R = 9 . 8 8 for 1981-2 and O R = 10.88 for 1983-4.
Chronic illness (females) F o r the females there was a clear gradient of increased reporting of chronic illness with age which was consistent over the two periods (Table II) and an excess in council tenants over owner occupiers ( O R = 1.38). An excess morbidity was also evident a m o n g s t the u r b a n females in the 1981-2 data. There appeared to be no clear S E G gradient. In addition the findings were suggestive that those with no access to cars experienced greater morbidity but this was only formally significant for the 1983-4 data.
Inequalities in Health Table I
Estimated odds ratios (OR) for chronic illness in males aged 1~64 1981-82
OR Age (yrs)
SEG
Tenure Access to cars Area Marital Status Deviance Degrees of freedom Table II
16-24 25-34 35-44 45-54 55~54 Upper SEG Inter. jun. nonmanual Skilled manual Lower SEG Own Council tenant Yes No Rural Urban Single Married
1.00 1.53 2.11 3.02 4.85 1.00 1.18 1.19 1.28 1.00 1.36 1.00 1.17 1.00 1.04 1.00 0.96 321.2 283
95% Confidence intervals (1.31,1.78) (1.80, 2.48) (2.57, 3.54) (4.13, 5.69) (1.04, 1.34) (1.07, 1.33) (1.12, 1.45) (1.24, 1.45) (1.07, 1.30) (0.95, 1.13) (0.85, 1.09)
OR
SEG
Tenure Access to cars Area Marital Status Deviance Degrees of freedom
1983-84 OR 1.00 1.44 2.06 3.05 5.28 1.00 1.29 1.21 1.41 1.00 1.26 1.00 1.16 1.00 0.93 181.3 149
95% Confidence intervals (1.23, (1.74, (2.58, (4.47,
1.70) 2.43) 3.61) 6.24)
(1.13, 1.47) (1.09, 1.35) (1.23, 1.60) (1.14, 1.39) (1.04, 1.29)
(0.82, 1.06)
Estimated odds ratios (OR) for chronic illness in females aged 16-64 1981-82
Age (yrs)
67
16-24 25-34 35-44 45-54 55-64 Upper SEG Inter. jun. nonmanual Skilled manual Lower SEG Own Council tenant Yes No Rural Urban Single Married
1.00 1.13 1.90 2.55 3.66 1.00 0.85 0.96 1.00 1.00 1.38 1.00 1.05 1.00 1.24 1.00 1.03 330.2 278
95% Confidence intervals (0.97, (1.63, (2.19, (3.14,
1.32) 2.22) 2.98) 4.27)
(0.71, 1.01) (0.78, 1.19) (0.83, 1.19) (1.26, 1.51) (0.95, 1.16) (1.13, 1.36) (0.91, 1.18)
1983-84 OR 1.00 1.22 1.70 2.89 4.10 1.00 1.05 1.13 1.13 1.00 1.38 1.00 1.18 1.00 1.02 156.0 142
95% Confidence intervals (1.04, (1.44, (2.45, (3.48,
1.44) 2.00) 3.41) 4.83)
(0.89, 1.24) (0.91, 1.40) (0.95, 1.34) (1.25, 1.52) (1.06, 1.31)
(0.89, 1.17)
P. Yuen et al.
68
Acute illness (males) The O R ' s summarised in Table I I I for reported acute illness in the males showed few consistent trends. Thus, for example, increased morbidity was not a simple function o f age although it was greatest in the 5 5 ~ 4 - y e a r age group in both periods. Likewise although those o f the upper socioeconomic group reported least acute illness, there was no obvious gradient across the other socioeconomic groups. Council tenants reported m o r e morbidity in both periods which was only significant in 1981-2. In contrast, although those with no access to cars also experienced greater morbidity, this was formally significant only for the years 1983-4. Married men reported m o r e acute illness but the corresponding confidence interval indicate lack o f formal statistical significance.
Acute illness (females) F o r females there were no consistent patterns with respect to age or socioeconomic group in reporting acute illness (Table IV). However council tenants, those with no access to a car and married w o m e n reported more morbidity in b o t h periods.
Discussion The General Household Survey provides information on a range of social variables from a representative sample o f individuals and households permitting linkage to health and other outcomes. However, it is a questionnaire survey which is not validated against external records, although it is performed by trained interviewers. Table III
Estimated odds ratios (OR) for acute illness in males aged 16~54 1981-82 OR
Age (yrs)
SEG
Tenure Access to cars Area Marital status Deviance Degrees of freedom
16-24 25-34 35-44 45-54 55~4 Upper SEG Inter. jun. nonmanual Skilled manual Lower SEG Own Council tenant Yes No Rural Urban Single Married
1.00 1.06 0.97 1.24 1.62 1.00 1.29 1.18 1.26 1.00 1.22 1.00 1. t3 1.00 0.97 1.00 1.05 310.8 283
95% Confidence intervals (0.85, (0.77, (0.98, (1.29,
1.30) 1.23) 1.56) 2.04)
(1.06, 1.57) (0.99, 1.40) (1.04, 1.54) (1.07, 1.39) (0.97, 1.30) (0.84, 1.10) (0.87, 1.25)
1983-84 OR 1.00 0.89 0.93 0.96 1.31 1.00 1.46 1.26 1.11 1.00 1.13 1.00 1.33 1.00 1.18 143.9 149
95% Confidence intervals (0.70, (0.74, (0.75, (1.0~
1.12) 1.18) 1.23) 1.66)
(1.20, 1.77) (1.06, 1.50) (0.91, 1.37) (0.98, 1.30) (1.14, 1.54)
(0.98, 1.42)
Inequalities in Health Table IV
Estimated odds ratios (OR) for acute illness in females aged 16-64 1981-82
OR Age (yrs)
SEG
Tenure Access to cars Area Marital status Deviance Degrees of freedom
69
16-24 25-34 35-44 45-54 55-64 Upper SEG Inter. Jun. nonmanual Skilled manual Lower SEG Own Council tenant Yes No Rural Urban Single Married
1.00 0.89 1.00 1.09 0.98 1.00 0.86 0.83 0.99 1.00 1.22 1.00 1.10 1.00 1.05 1.00 1.21 302.0 278
95% Confidence intervals (0.74, (0.82, (0.89, (0.80,
1.09) 1.22) 1.33) 1.20)
(0.68, 1.09) (0.62, 1.12) (0.77, 1.26) (1.08, 1.37) (0.97, 1.26) (0.93, 1.19) (1.01, 1.44)
1983-84 OR 1.00 1.08 1.03 1.14 1.35 1.00 0.97 1.01 0.91 1.00 1.21 1.00 1.18 1.00 1.20 157.6 142
9 5 0 Confidence intervals (0.89, (0.83, (0.92, (1.10,
i.32) 1.26) 1.41) 1.67)
(0.78, 1.21) (0.77, 1.33) (0.72, 1.14) (1.06, 1.38) (1.03, 1.36)
(1.00, 1.44)
We report here on acute and chronic illness. The former related to restricted activity in the 14 days before the interview and the latter to long-standing illness. These are measures o f self-reported morbidity and it is recognised that perceptions of health need are known to be different between social g r o u p s ) T M Variations in morbidity appeared to be well described by main effect models except for chronic illness in females in w h o m a substantial proportion o f the total variation was nevertheless explained. The O R ' s suggest a clear gradient for both chronic and acute illness with council tenure being associated with more self-reported morbidity in both sexes. Although for chronic illness there is a clear socioeconomic gradient with lowering socioeconomic group in males, this is not consistently reflected in acute illness reporting or for both measures o f morbidity in females. There is more morbidity reported in those with no access to cars. As expected there is increasing morbidity reported with age in both sexes although this trend is more clearly seen with chronic illness. U r b a n females report excesses o f chronic illness, but area o f residence appears to have little effect on the acute morbidity of the females. These results correspond to our previously published findings on the socioeconomic differentials in the uptake o f c a r e ) 5 In the former study which was restricted to men, tenure appeared to be the most important social variable effecting the uptake o f care. Men in manual occupations not only consulted doctors more often, but more often utilised both outpatient and inpatient facilities, than those in the n o n - m a n u a l group. Lack o f access to cars appeared to act as a surrogate for social means for inpatient attendance though presence o f a car appeared to facilitate both consultation o f doctors and attendance at
70
P. Yuen et al.
outpatient clinics. Thus the present findings provide further evidence o f the wide socioeconomic differences in morbidity that are currently prevalent. Inequalities in health, as demonstrated by differentials in mortality between social classes, was brought to the forefront by the publication o f the Black report.16 Differences in morbidity in relation to social class are also well established. 17 Previous studies on morbidity have not however simultaneously examined the m a n y social variables and their possible interactions that could influence morbidity. Our findings show clear independent differentials for many social variables in self-reported morbidity among both men and women in Great Britain. These gradients are not only independent but have in combination a multiplicative influence on the state of health. Though self-reported morbidity has its limitations, it has been shown that physicians and patient ratings o f health are consistent, is,19 The relationships between the social variables examined in this study and the state o f health are complex. Some factors like housing could have a more direct influence on health status through lack of facilities and amenities, lack o f adequate heating and overcrowding. Other ingredients assumed with lower social status, such as unhealthy life style especially smoking and dietary habits, could explain some of the differentials together with occupational hazards, which are also likely to be greater in those o f lower social status. It is also possible that the state o f health itself could lead to p o o r social status though, on balance, the overwhelming evidence is for p o o r social status to lead to ill health. Researchers have also proposed that 'social stress' could have a non-specific influence in inducing ill health. 2° Differential access and the non optimal utilisation o f health care are factors related to the health service that could contribute to continuing inequalities in Britain. Preventive services are known to be taken up to a lesser extent by those from p o o r socioeconomic backgrounds. 2L22 The socioeconomic differences shown in this study are likely to vary with time as the social structure o f society changes. We are exploring further the possible regional differences that might exist. Present-day inequalities at a national level are however substantial and could not be alleviated by health care intervention alone though there is scope for major initiatives. These must involve health promotion and preventative campaigns specially targeted at the disadvantaged and providing equity o f access to all aspects of health care particularly, primary care. Doctors are known to communicate better with patients with middle class backgrounds 23 so that greater emphasis should be given to exposure, at an early stage in the training o f doctors and other health care personnel, to both social and community issues. It is also imperative that health is not looked at in isolation but in the wider social context. If 'Health for all' is to be achieved by the turn of the century, 24'25 adequate investment in social programmes must be considered now to create the necessary infrastructure. Public health physicians should provide the lead in these respects. References
1. Office of Population Censuses and Surveys. (1986). Registrar General's decennial supplement on occupational mortality 1979-83. London: HMSO. 2. Marmot, M. G. & McDowalt, M. E. (1986). Mortality decline and widening social inequalities. Lancet, ii, 274-276. 3. Health Education Council. (1987). Health Divide. 4. Balarajan, R. & McDowall, M. E. (1988). Regional socioeconomic differences in mortality among men in Great Britain today. Public Health, 102, 33-43.
Inequalities in Health
71
5. Balarajan, R., Yuen, P. & Machin, D. (1987). Inequalities in Health: changes in RHAs in the past decade. British Medical Journal, 294, 1561-1564. 6. Leete, R. & Fox, A. J. (1977). Registrar General's social class origins and uses. Population Trends, 8, 1-7. 7. Fox, A. J. & Goldblatt, P. O. (1982). Longitudinal Study: Socioeconomic Mortality Differentials 1971-5. Office of Population Censuses and Surveys. London: HMSO. 8. Office of Population Censuses and Surveys. (1983). General Household Survey 1981. London: HMSO. 9. Office of Population Censuses and Surveys. (1984). General Household Survey 1982. London: HMSO. 10. Office of Population Censuses and Surveys. (1985). General Household Survey 1983. London: HMSO. 11. Office of Population Censuses and Surveys. (1986). General Household Survey 1984. London: HMSO. 12. Baker, R. J. & Nelder, J. A. (1985). G L I M System (Release 3.77). Oxford: Numerical Algorithm Group. 13. Dunnell, K. & Cartwright, A. (1972). Medicine takers, prescribers and hoarders. London: Routledge & Kegan Paul. 14. Cameron, A. & Hinton, J. (1968). Delay in seeking treatment for mammary tumours. Cancer, 21, 1121-1126. 15. Balarajan, R., Yuen, P. & Machin, D. (1987). Socioeconomic differentials in the uptake of medical care in Great Britain. Journal of Epidemiology and Community Health, 41, 196-199. 16. Black, D., Morris, J. N., Smith, C. & Townsend, P. (1982). Inequalities in health. Suffolk: Chaucer Press (Black Report). 17. Carstairs, V. (1981). Multiple deprivation and Health State. Community Medicine, 3, 4-13. 18. Carstairs, V. (1982). Health and social deprivation. In: Recent Advances in Community Medicine Number 2 Smith A. (ed). Churchill Livingstone. 19. Maddox, G. L. & Douglas, E. B. (1973). Self assessment of health: a longitudinal study of elderly subjects. Journal of Health and Social Behaviour, 14, 87. 20. Marmot, M. G., Shipley, M. J. & Rose, G. (1984). Inequalities in death - specific explanations of a general pattern? Lancet, i, 1003-6. 21. Heasman, M. A. (1961). Mass miniature radiography. Studies on Medical and Population subjects No 17. General Registrar Office. London: HMSO. 22. Osborn, G. R. & Leyshon, V. N. (1966). Domiciliary testing of cervical smears by home nurses. Lancet, i, 256. 23. Cartwright, A. & O'Brien, M. (1976). Social class variations in health care and in the nature of General Practitioner consultation. In: The Sociology of the National Health Service. Stracey, M. (ed). University of Keele. 24. World Health Organization (1985). Targets for health for all 2000. Copenhagen: WHO. 25. Faculty of Community Medicine (1986). Health for all by the year 2000. Charter for action. London: Faculty of Community Medicine.
© The Societyof Public Health, 1990
Inequalities in Health" Socioeconomic Differences in Self-Reported Morbidity P. Y u e n 1, D. M a c h i n 1"2 and R. Balarajan 1
1Epidemiology and Public Health Research Unit, University of Surrey, Gui/dford, Surrey GU2 5XH; 2Medical Research Council, Cancer Trials Office, Shaftsbury Road, Cambridge CB2 2BW
Socioeconomic differences in self-reported chronic and acute illness were investigated in men and women using data from the General Household Surveys (1981-4). Logit models were used to investigate the influence of age, socioeconomic group, tenure, access to cars, area of residence and marital status on these measures of morbidity. For both measures local authority tenants, whether male or female, reported the most morbidity as did those with no access to cars. Both males and females reported increasing levels of illness the lower their socioeconomic group but similar patterns were not observed with acute illness. The significance of these present day inequalities is discussed.
Introduction Publication of the Registrar General's latest decennial supplement on occupational mortality I provided the most recent evidence on inequalities in health as measured by mortality differences across social class groups. Examination o f the data for successive decennial supplements showed evidence o f the widening of such inequalities nationally, over the past d e c a d e Y Regional differences in inequalities have also been demonstrated using the latest decennial supplement 4 and there is further evidence for the widening o f such inequalities in some Health Regions. 5 A p a r t from the Registrar General's social class, 6 other socioeconomic variables such as housing tenure, access to cars, have been shown to have independent contributions to mortality levels. 7 In this study we have examined inequalities in health in terms o f morbidity across a r a n g e o f social variables for the period roughly corresponding to the latest decennial supplement using the General Household Surveys o f 1981-4. 8-H
Materials and methods The General Household Survey (GHS) is an annual sample survey o f the population resident in private households in Great Britain, conducted by the Office o f Population Censuses and Surveys. D a t a are available on some 30,000 individuals aged 16 and above, on a wide range o f social variables including socioeconomic groups, marital status, access to cars, housing, employment, area o f residence and health. The socioeconomic status of married women is recorded as that o f their present or last jobs. A m o n g the questions on health the G H S elicit information on chronic illness and on acute illness. Acute illness is defined as that which causes restriction o f activity in the 14 days preceding the interview.
66
P. Yuen et al.
The question on chronic illness asks the individuals whether they have any long-standing illness, disability or infirmity. D a t a relating to the surveys 1981-4 were used for this analysis. The years 1981-2 and 1983-4 were pooled separately to obtain sufficient numbers in cells in the corresponding cross-tabulations but yet enable examination o f possible changes with time. We confined our attention to responses concerning those less than 65 as a relatively large p r o p o r t i o n of those over this age are in specialised residential accommodation which is not sampled by the G H S . Preliminary analysis suggested that the six abbreviated socioeconomic groups used by the G H S could be further regrouped into four relatively homogeneous categories. We term these upper, intermediate, junior non-manual, skilled m a n u a l and lower socioeconomic groups. The urban/rural classification was not available for the 1984 data. For each sex the probability of a health outcome (episodes of chronic and acute illness separately) was modelled with respect to age, socioeconomic group, tenure (local authority tenant or owner occupier), access to cars, area o f residence (urban or rural) and marital status by means o f logistic regression. A null model would correspond to the situation in which none o f the variables under study appears to influence the probability o f a particular health outcome. The models considered, first included all main effects and associated interaction terms and then a selection procedure was adopted to choose a reduced model in which only the important variables and interactions with respect to the particular health outcome were included. Once a satisfactory model was chosen estimates o f odds ratios (OR) and corresponding 95 % confidence intervals were calculated. A measure of goodness o f fit of the model is provided by the deviance which is distributed approximately as a chi-squared distribution with the appropriate degrees of freedom. In the event it turned out that for all situations considered here a model, including main effects only, explained a substantial proportion o f the variation. The statistical package G L I M l: was used to fit the models, for completeness non-significant main effect terms are also summarised in the results section. Results
Chronic illness (males) The O R ' s for the various at risk groups derived f r o m the main effects model for self-reported chronic illness in the males are summarised in Table I. There was an increase in reported morbidity with lowering of socioeconomic group and excess reporting amongst council tenants and those without access to cars. There was a general increase in reporting with age. A close correspondence between the O R ' s for each risk group was evident for each two-year interval. The highest reporting group were the 55-64-year-old council tenants o f lower socioeconomic group, with no access to car O R = 9 . 8 8 for 1981-2 and O R = 10.88 for 1983-4.
Chronic illness (females) F o r the females there was a clear gradient of increased reporting of chronic illness with age which was consistent over the two periods (Table II) and an excess in council tenants over owner occupiers ( O R = 1.38). An excess morbidity was also evident a m o n g s t the u r b a n females in the 1981-2 data. There appeared to be no clear S E G gradient. In addition the findings were suggestive that those with no access to cars experienced greater morbidity but this was only formally significant for the 1983-4 data.
Inequalities in Health Table I
Estimated odds ratios (OR) for chronic illness in males aged 1~64 1981-82
OR Age (yrs)
SEG
Tenure Access to cars Area Marital Status Deviance Degrees of freedom Table II
16-24 25-34 35-44 45-54 55~54 Upper SEG Inter. jun. nonmanual Skilled manual Lower SEG Own Council tenant Yes No Rural Urban Single Married
1.00 1.53 2.11 3.02 4.85 1.00 1.18 1.19 1.28 1.00 1.36 1.00 1.17 1.00 1.04 1.00 0.96 321.2 283
95% Confidence intervals (1.31,1.78) (1.80, 2.48) (2.57, 3.54) (4.13, 5.69) (1.04, 1.34) (1.07, 1.33) (1.12, 1.45) (1.24, 1.45) (1.07, 1.30) (0.95, 1.13) (0.85, 1.09)
OR
SEG
Tenure Access to cars Area Marital Status Deviance Degrees of freedom
1983-84 OR 1.00 1.44 2.06 3.05 5.28 1.00 1.29 1.21 1.41 1.00 1.26 1.00 1.16 1.00 0.93 181.3 149
95% Confidence intervals (1.23, (1.74, (2.58, (4.47,
1.70) 2.43) 3.61) 6.24)
(1.13, 1.47) (1.09, 1.35) (1.23, 1.60) (1.14, 1.39) (1.04, 1.29)
(0.82, 1.06)
Estimated odds ratios (OR) for chronic illness in females aged 16-64 1981-82
Age (yrs)
67
16-24 25-34 35-44 45-54 55-64 Upper SEG Inter. jun. nonmanual Skilled manual Lower SEG Own Council tenant Yes No Rural Urban Single Married
1.00 1.13 1.90 2.55 3.66 1.00 0.85 0.96 1.00 1.00 1.38 1.00 1.05 1.00 1.24 1.00 1.03 330.2 278
95% Confidence intervals (0.97, (1.63, (2.19, (3.14,
1.32) 2.22) 2.98) 4.27)
(0.71, 1.01) (0.78, 1.19) (0.83, 1.19) (1.26, 1.51) (0.95, 1.16) (1.13, 1.36) (0.91, 1.18)
1983-84 OR 1.00 1.22 1.70 2.89 4.10 1.00 1.05 1.13 1.13 1.00 1.38 1.00 1.18 1.00 1.02 156.0 142
95% Confidence intervals (1.04, (1.44, (2.45, (3.48,
1.44) 2.00) 3.41) 4.83)
(0.89, 1.24) (0.91, 1.40) (0.95, 1.34) (1.25, 1.52) (1.06, 1.31)
(0.89, 1.17)
P. Yuen et al.
68
Acute illness (males) The O R ' s summarised in Table I I I for reported acute illness in the males showed few consistent trends. Thus, for example, increased morbidity was not a simple function o f age although it was greatest in the 5 5 ~ 4 - y e a r age group in both periods. Likewise although those o f the upper socioeconomic group reported least acute illness, there was no obvious gradient across the other socioeconomic groups. Council tenants reported m o r e morbidity in both periods which was only significant in 1981-2. In contrast, although those with no access to cars also experienced greater morbidity, this was formally significant only for the years 1983-4. Married men reported m o r e acute illness but the corresponding confidence interval indicate lack o f formal statistical significance.
Acute illness (females) F o r females there were no consistent patterns with respect to age or socioeconomic group in reporting acute illness (Table IV). However council tenants, those with no access to a car and married w o m e n reported more morbidity in b o t h periods.
Discussion The General Household Survey provides information on a range of social variables from a representative sample o f individuals and households permitting linkage to health and other outcomes. However, it is a questionnaire survey which is not validated against external records, although it is performed by trained interviewers. Table III
Estimated odds ratios (OR) for acute illness in males aged 16~54 1981-82 OR
Age (yrs)
SEG
Tenure Access to cars Area Marital status Deviance Degrees of freedom
16-24 25-34 35-44 45-54 55~4 Upper SEG Inter. jun. nonmanual Skilled manual Lower SEG Own Council tenant Yes No Rural Urban Single Married
1.00 1.06 0.97 1.24 1.62 1.00 1.29 1.18 1.26 1.00 1.22 1.00 1. t3 1.00 0.97 1.00 1.05 310.8 283
95% Confidence intervals (0.85, (0.77, (0.98, (1.29,
1.30) 1.23) 1.56) 2.04)
(1.06, 1.57) (0.99, 1.40) (1.04, 1.54) (1.07, 1.39) (0.97, 1.30) (0.84, 1.10) (0.87, 1.25)
1983-84 OR 1.00 0.89 0.93 0.96 1.31 1.00 1.46 1.26 1.11 1.00 1.13 1.00 1.33 1.00 1.18 143.9 149
95% Confidence intervals (0.70, (0.74, (0.75, (1.0~
1.12) 1.18) 1.23) 1.66)
(1.20, 1.77) (1.06, 1.50) (0.91, 1.37) (0.98, 1.30) (1.14, 1.54)
(0.98, 1.42)
Inequalities in Health Table IV
Estimated odds ratios (OR) for acute illness in females aged 16-64 1981-82
OR Age (yrs)
SEG
Tenure Access to cars Area Marital status Deviance Degrees of freedom
69
16-24 25-34 35-44 45-54 55-64 Upper SEG Inter. Jun. nonmanual Skilled manual Lower SEG Own Council tenant Yes No Rural Urban Single Married
1.00 0.89 1.00 1.09 0.98 1.00 0.86 0.83 0.99 1.00 1.22 1.00 1.10 1.00 1.05 1.00 1.21 302.0 278
95% Confidence intervals (0.74, (0.82, (0.89, (0.80,
1.09) 1.22) 1.33) 1.20)
(0.68, 1.09) (0.62, 1.12) (0.77, 1.26) (1.08, 1.37) (0.97, 1.26) (0.93, 1.19) (1.01, 1.44)
1983-84 OR 1.00 1.08 1.03 1.14 1.35 1.00 0.97 1.01 0.91 1.00 1.21 1.00 1.18 1.00 1.20 157.6 142
9 5 0 Confidence intervals (0.89, (0.83, (0.92, (1.10,
i.32) 1.26) 1.41) 1.67)
(0.78, 1.21) (0.77, 1.33) (0.72, 1.14) (1.06, 1.38) (1.03, 1.36)
(1.00, 1.44)
We report here on acute and chronic illness. The former related to restricted activity in the 14 days before the interview and the latter to long-standing illness. These are measures o f self-reported morbidity and it is recognised that perceptions of health need are known to be different between social g r o u p s ) T M Variations in morbidity appeared to be well described by main effect models except for chronic illness in females in w h o m a substantial proportion o f the total variation was nevertheless explained. The O R ' s suggest a clear gradient for both chronic and acute illness with council tenure being associated with more self-reported morbidity in both sexes. Although for chronic illness there is a clear socioeconomic gradient with lowering socioeconomic group in males, this is not consistently reflected in acute illness reporting or for both measures o f morbidity in females. There is more morbidity reported in those with no access to cars. As expected there is increasing morbidity reported with age in both sexes although this trend is more clearly seen with chronic illness. U r b a n females report excesses o f chronic illness, but area o f residence appears to have little effect on the acute morbidity of the females. These results correspond to our previously published findings on the socioeconomic differentials in the uptake o f c a r e ) 5 In the former study which was restricted to men, tenure appeared to be the most important social variable effecting the uptake o f care. Men in manual occupations not only consulted doctors more often, but more often utilised both outpatient and inpatient facilities, than those in the n o n - m a n u a l group. Lack o f access to cars appeared to act as a surrogate for social means for inpatient attendance though presence o f a car appeared to facilitate both consultation o f doctors and attendance at
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outpatient clinics. Thus the present findings provide further evidence o f the wide socioeconomic differences in morbidity that are currently prevalent. Inequalities in health, as demonstrated by differentials in mortality between social classes, was brought to the forefront by the publication o f the Black report.16 Differences in morbidity in relation to social class are also well established. 17 Previous studies on morbidity have not however simultaneously examined the m a n y social variables and their possible interactions that could influence morbidity. Our findings show clear independent differentials for many social variables in self-reported morbidity among both men and women in Great Britain. These gradients are not only independent but have in combination a multiplicative influence on the state of health. Though self-reported morbidity has its limitations, it has been shown that physicians and patient ratings o f health are consistent, is,19 The relationships between the social variables examined in this study and the state o f health are complex. Some factors like housing could have a more direct influence on health status through lack of facilities and amenities, lack o f adequate heating and overcrowding. Other ingredients assumed with lower social status, such as unhealthy life style especially smoking and dietary habits, could explain some of the differentials together with occupational hazards, which are also likely to be greater in those o f lower social status. It is also possible that the state o f health itself could lead to p o o r social status though, on balance, the overwhelming evidence is for p o o r social status to lead to ill health. Researchers have also proposed that 'social stress' could have a non-specific influence in inducing ill health. 2° Differential access and the non optimal utilisation o f health care are factors related to the health service that could contribute to continuing inequalities in Britain. Preventive services are known to be taken up to a lesser extent by those from p o o r socioeconomic backgrounds. 2L22 The socioeconomic differences shown in this study are likely to vary with time as the social structure o f society changes. We are exploring further the possible regional differences that might exist. Present-day inequalities at a national level are however substantial and could not be alleviated by health care intervention alone though there is scope for major initiatives. These must involve health promotion and preventative campaigns specially targeted at the disadvantaged and providing equity o f access to all aspects of health care particularly, primary care. Doctors are known to communicate better with patients with middle class backgrounds 23 so that greater emphasis should be given to exposure, at an early stage in the training o f doctors and other health care personnel, to both social and community issues. It is also imperative that health is not looked at in isolation but in the wider social context. If 'Health for all' is to be achieved by the turn of the century, 24'25 adequate investment in social programmes must be considered now to create the necessary infrastructure. Public health physicians should provide the lead in these respects. References
1. Office of Population Censuses and Surveys. (1986). Registrar General's decennial supplement on occupational mortality 1979-83. London: HMSO. 2. Marmot, M. G. & McDowalt, M. E. (1986). Mortality decline and widening social inequalities. Lancet, ii, 274-276. 3. Health Education Council. (1987). Health Divide. 4. Balarajan, R. & McDowall, M. E. (1988). Regional socioeconomic differences in mortality among men in Great Britain today. Public Health, 102, 33-43.
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5. Balarajan, R., Yuen, P. & Machin, D. (1987). Inequalities in Health: changes in RHAs in the past decade. British Medical Journal, 294, 1561-1564. 6. Leete, R. & Fox, A. J. (1977). Registrar General's social class origins and uses. Population Trends, 8, 1-7. 7. Fox, A. J. & Goldblatt, P. O. (1982). Longitudinal Study: Socioeconomic Mortality Differentials 1971-5. Office of Population Censuses and Surveys. London: HMSO. 8. Office of Population Censuses and Surveys. (1983). General Household Survey 1981. London: HMSO. 9. Office of Population Censuses and Surveys. (1984). General Household Survey 1982. London: HMSO. 10. Office of Population Censuses and Surveys. (1985). General Household Survey 1983. London: HMSO. 11. Office of Population Censuses and Surveys. (1986). General Household Survey 1984. London: HMSO. 12. Baker, R. J. & Nelder, J. A. (1985). G L I M System (Release 3.77). Oxford: Numerical Algorithm Group. 13. Dunnell, K. & Cartwright, A. (1972). Medicine takers, prescribers and hoarders. London: Routledge & Kegan Paul. 14. Cameron, A. & Hinton, J. (1968). Delay in seeking treatment for mammary tumours. Cancer, 21, 1121-1126. 15. Balarajan, R., Yuen, P. & Machin, D. (1987). Socioeconomic differentials in the uptake of medical care in Great Britain. Journal of Epidemiology and Community Health, 41, 196-199. 16. Black, D., Morris, J. N., Smith, C. & Townsend, P. (1982). Inequalities in health. Suffolk: Chaucer Press (Black Report). 17. Carstairs, V. (1981). Multiple deprivation and Health State. Community Medicine, 3, 4-13. 18. Carstairs, V. (1982). Health and social deprivation. In: Recent Advances in Community Medicine Number 2 Smith A. (ed). Churchill Livingstone. 19. Maddox, G. L. & Douglas, E. B. (1973). Self assessment of health: a longitudinal study of elderly subjects. Journal of Health and Social Behaviour, 14, 87. 20. Marmot, M. G., Shipley, M. J. & Rose, G. (1984). Inequalities in death - specific explanations of a general pattern? Lancet, i, 1003-6. 21. Heasman, M. A. (1961). Mass miniature radiography. Studies on Medical and Population subjects No 17. General Registrar Office. London: HMSO. 22. Osborn, G. R. & Leyshon, V. N. (1966). Domiciliary testing of cervical smears by home nurses. Lancet, i, 256. 23. Cartwright, A. & O'Brien, M. (1976). Social class variations in health care and in the nature of General Practitioner consultation. In: The Sociology of the National Health Service. Stracey, M. (ed). University of Keele. 24. World Health Organization (1985). Targets for health for all 2000. Copenhagen: WHO. 25. Faculty of Community Medicine (1986). Health for all by the year 2000. Charter for action. London: Faculty of Community Medicine.
