997
MORTALITY, MORBIDITY, AND RESOURCE ALLOCATION D. P. FORSTER Medical Care Research Unit, Department of Community Medicine, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX
The correlation between age and sex standardised mortality-rates, and morbidity-rates from the General Household Survey (G.H.S.) similarly standardised, were examined for the 10 standard statistical regions for 1972 and 1973 combined. The correlations between mortality and acute sickness and between mortality and bed sickness were not significant. A significant correlation was found between mortality and chronic sickness, but not between mortality and work or school absence due to illness or injury in males. It is concluded that, on present evidence, there is some doubt whether mortality can be considered to be a valid indicator of morbidity in a population. Serious consideration should therefore be given to the removal of standardised mortality ratios (S.M.R.S) from the formula for the distribution of revenue as recommended by the Resource Allocation Working Party (RAWP).
Summary
INTRODUCTION
THE report of the Resource Allocation Working Party recommended fundamental changes in the formula for the distribution of revenue to the regional health authorities (R.H.A.S ).1 A basic component in the new formula is mortality, measured by standardised mortality ratios S,M.R.S. The working-party recommended that in the assessment of the relative need for health care, s.M.R.s for each R.H.A. should be introduced into the population weightings as a proxy for morbidity. The s.M.R. would be on a condition-specific basis for acute non-psychiatric hospital inpatient services, and on an overall basis for non-psychiatric day and outpatient services, for community health services, and for ambulance services. The working-party established that overall s.M.R.s when applied to inpatients gave broadly the same results as
condition-specific S.M.R.S. The critical question is how
accurate mortality is as indicator of the relative need for health care in a population. Previous work has suggested that mortality is a sensitive indicator of the health status of a population in developed countries only when infectious diseases are a major health problem.2 Similarly, a World Health
Organisation report considered that where the numbers of deaths per year in the age range 1 week to 5 5 years are small, mortality-rates are unlikely to reflect the need for medical care.3 In contrast, RAwp supported the use of mortality as a proxy for morbidity by suggesting significant positive correlations between s.M.R.s and agestandardised morbidity derived from the G.H.s. for the standard statistical regions of England and Wales. This evidence, based on the data for the single year of 1972, is open to challenge, since the G.H.S. is carried out annually on a sample of the population drawn in a complex manner (a three-stage, stratified rotating sample design).4 Some apparent differences in morbidity between standard regions, based on a single year’s data, may be attributable to sampling variation.5 METHOD
In the present study the sampling error of G.H.S. morbidity data has been reduced, and hence the accuracy increased, by combining data for two years. Morbidity information from the G.H.S. is not available for R.H.A.s, but is available for the standard statistical regions of England and Wales. Comparisons between age and sex standardised morbidity data and age and sex standardised mortality data for the combined years of 1972 and 1973 were carried out for the 10 standard regions. All data were age and sex standardised by the direct method with the 1971 census population for England and Wales as the standard. The direct method of age-standardisation was chosen in preference to the indirect method since no adequate standardising-rates for morbidity from an external population were available. Direct age-standardised mortality-rates provide essentially the same results as S.M.R.S, since the rank ordering of the standard regions and the variation between them are identical. The following morbidity indicators from the G.H.s. for 1972 and 1973 combined were used:
Acute sickness
(including
the exacerbation of chronic sickor in-
ness)-restriction of normal activities because of illness jury during a two-week reference period.
Bed sickness-acute sickness necessitating a stay in bed during a two-week reference period. Chronic sickness-a state of long-standing illness, disability, or infirmity. Work or school absence-acute sickness necessitating time off work or school, during a two-week reference period (this includes uncertificated absence).
an
45. Purola, T., Kalimo, E., Sievers, K., Nyman, K. The Utilisation of the Medical Services and its relation to Morbidity, Health Resources and Social Factors: a Survey of the Population of Finland Prior to National Sickness Insurance Scheme. Helsinki, 1968. 46. Purola, T. Kalimo, E., Nyman, K. Health Service Use and Health Status under National Sickness Insurance: an Evaluative Re-survey of Finland.
Helsinki, 1974. Rowe, R. G., Brewer, W. Hospital Activity Analysis. London, 1972. Logan, R. F. L., Ashley, J. S. A., Klein, R. E., Robson, D. M. Dynamics of Medical Care: the Liverpool Study into Use of Hospital Resources. London School of Hygiene and Tropical Medicine, memoir no. 14, 1972. 49 Culyer, A. J. in Health Economics (edited by M. H. Cooper and A. J. Culyer). London, 1971. 50 Hauser, M. M (editor) The Economics of Medical Care. London, 1972. 51 Powell, J. E. Medicine and Politics: 1975 and After. Tunbridge Wells, 1976. 52 Doll, R. To Measure N.H.S. Progress. Fabian Society Interim Occasional Paper, no. 8. London, 1974. 53 de Kadt, E. New Society, 1976, 36, 525.
47 48
RESULTS
shows the age and sex standardised rates and rankfor mortality and morbidity indicators for the standard statistical regions in the combined years of 1972 and 1973. There are considerable differences in the ranking order. For example, the North West standard region ranks highest for mortality but sixth for acute sickness and fifth for bed sickness. The Greater London Council ranks seventh for mortality but second for acute sickness and third for bed sickness. Application of Spearman’s rank order correlation coefficient’ revealed no significant overall correlation between mortality and acute sickness or between mortality and bed sickness. Fewer large differences in the ranking order were found between mortality and chronic sickness, and the rank order correlation coefficient between these two indicators is signifiTable
i
ing order
cant
(p
MORTALITY, MORBIDITY, AND RESOURCE ALLOCATION D. P. FORSTER Medical Care Research Unit, Department of Community Medicine, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX
The correlation between age and sex standardised mortality-rates, and morbidity-rates from the General Household Survey (G.H.S.) similarly standardised, were examined for the 10 standard statistical regions for 1972 and 1973 combined. The correlations between mortality and acute sickness and between mortality and bed sickness were not significant. A significant correlation was found between mortality and chronic sickness, but not between mortality and work or school absence due to illness or injury in males. It is concluded that, on present evidence, there is some doubt whether mortality can be considered to be a valid indicator of morbidity in a population. Serious consideration should therefore be given to the removal of standardised mortality ratios (S.M.R.S) from the formula for the distribution of revenue as recommended by the Resource Allocation Working Party (RAWP).
Summary
INTRODUCTION
THE report of the Resource Allocation Working Party recommended fundamental changes in the formula for the distribution of revenue to the regional health authorities (R.H.A.S ).1 A basic component in the new formula is mortality, measured by standardised mortality ratios S,M.R.S. The working-party recommended that in the assessment of the relative need for health care, s.M.R.s for each R.H.A. should be introduced into the population weightings as a proxy for morbidity. The s.M.R. would be on a condition-specific basis for acute non-psychiatric hospital inpatient services, and on an overall basis for non-psychiatric day and outpatient services, for community health services, and for ambulance services. The working-party established that overall s.M.R.s when applied to inpatients gave broadly the same results as
condition-specific S.M.R.S. The critical question is how
accurate mortality is as indicator of the relative need for health care in a population. Previous work has suggested that mortality is a sensitive indicator of the health status of a population in developed countries only when infectious diseases are a major health problem.2 Similarly, a World Health
Organisation report considered that where the numbers of deaths per year in the age range 1 week to 5 5 years are small, mortality-rates are unlikely to reflect the need for medical care.3 In contrast, RAwp supported the use of mortality as a proxy for morbidity by suggesting significant positive correlations between s.M.R.s and agestandardised morbidity derived from the G.H.s. for the standard statistical regions of England and Wales. This evidence, based on the data for the single year of 1972, is open to challenge, since the G.H.S. is carried out annually on a sample of the population drawn in a complex manner (a three-stage, stratified rotating sample design).4 Some apparent differences in morbidity between standard regions, based on a single year’s data, may be attributable to sampling variation.5 METHOD
In the present study the sampling error of G.H.S. morbidity data has been reduced, and hence the accuracy increased, by combining data for two years. Morbidity information from the G.H.S. is not available for R.H.A.s, but is available for the standard statistical regions of England and Wales. Comparisons between age and sex standardised morbidity data and age and sex standardised mortality data for the combined years of 1972 and 1973 were carried out for the 10 standard regions. All data were age and sex standardised by the direct method with the 1971 census population for England and Wales as the standard. The direct method of age-standardisation was chosen in preference to the indirect method since no adequate standardising-rates for morbidity from an external population were available. Direct age-standardised mortality-rates provide essentially the same results as S.M.R.S, since the rank ordering of the standard regions and the variation between them are identical. The following morbidity indicators from the G.H.s. for 1972 and 1973 combined were used:
Acute sickness
(including
the exacerbation of chronic sickor in-
ness)-restriction of normal activities because of illness jury during a two-week reference period.
Bed sickness-acute sickness necessitating a stay in bed during a two-week reference period. Chronic sickness-a state of long-standing illness, disability, or infirmity. Work or school absence-acute sickness necessitating time off work or school, during a two-week reference period (this includes uncertificated absence).
an
45. Purola, T., Kalimo, E., Sievers, K., Nyman, K. The Utilisation of the Medical Services and its relation to Morbidity, Health Resources and Social Factors: a Survey of the Population of Finland Prior to National Sickness Insurance Scheme. Helsinki, 1968. 46. Purola, T. Kalimo, E., Nyman, K. Health Service Use and Health Status under National Sickness Insurance: an Evaluative Re-survey of Finland.
Helsinki, 1974. Rowe, R. G., Brewer, W. Hospital Activity Analysis. London, 1972. Logan, R. F. L., Ashley, J. S. A., Klein, R. E., Robson, D. M. Dynamics of Medical Care: the Liverpool Study into Use of Hospital Resources. London School of Hygiene and Tropical Medicine, memoir no. 14, 1972. 49 Culyer, A. J. in Health Economics (edited by M. H. Cooper and A. J. Culyer). London, 1971. 50 Hauser, M. M (editor) The Economics of Medical Care. London, 1972. 51 Powell, J. E. Medicine and Politics: 1975 and After. Tunbridge Wells, 1976. 52 Doll, R. To Measure N.H.S. Progress. Fabian Society Interim Occasional Paper, no. 8. London, 1974. 53 de Kadt, E. New Society, 1976, 36, 525.
47 48
RESULTS
shows the age and sex standardised rates and rankfor mortality and morbidity indicators for the standard statistical regions in the combined years of 1972 and 1973. There are considerable differences in the ranking order. For example, the North West standard region ranks highest for mortality but sixth for acute sickness and fifth for bed sickness. The Greater London Council ranks seventh for mortality but second for acute sickness and third for bed sickness. Application of Spearman’s rank order correlation coefficient’ revealed no significant overall correlation between mortality and acute sickness or between mortality and bed sickness. Fewer large differences in the ranking order were found between mortality and chronic sickness, and the rank order correlation coefficient between these two indicators is signifiTable
i
ing order
cant
(p
