1 THE DISTRIBUTION AND DETERMINANTS OF PRIVATE HEALTH INSURANCE IN AUSTRALIA, 1990 Deborah Schofield Discussion Paper No. 17 May 1997
2 National Centre for Social and Economic Modelling Faculty of Management University of Canberra The National Centre for Social and Economic Modelling was established on 1 January 1993, following a contract between the University of Canberra and the then federal Department of Health, Housing, Local Government and Community Services (now Health and Family Services). NATSEM aims to enhance social and economic policy debate and analysis by developing high quality models, applying them in relevant research and supplying consultancy services. NATSEM s key area of expertise lies in developing and using microdata and microsimulation models for a range of purposes, including analysing the distributional impact of social and economic policy. The NATSEM models are usually based on individual records of real (but unidentifiable) Australians. This base produces great flexibility, as results can be derived for small subgroups of the population or for all of Australia. NATSEM ensures that the results of its work are made widely available by publishing details of its products and research findings. Its technical and discussion papers are produced by NATSEM s research staff or visitors to the centre, are the product of collaborative efforts with other organisations and individuals, or arise from commissioned research (such as conferences). Discussion papers present preliminary research findings and are only lightly refereed. Its policy papers are designed to provide rapid input to current policy debates and are not externally refereed. It must be emphasised that NATSEM does not have views on policy and that all opinions are the authors own. Director: Ann Harding
3 National Centre for Social and Economic Modelling Faculty of Management University of Canberra THE DISTRIBUTION AND DETERMINANTS OF PRIVATE HEALTH INSURANCE IN AUSTRALIA, 1990 Deborah Schofield Discussion Paper No. 17 May 1997
4 ISSN ISBN NATSEM, University of Canberra 1998 National Centre for Social and Economic Modelling GPO Box 563 Canberra ACT 2601 Australia Phone: Fax: Client services General World Wide Web site Core funding for NATSEM is provided by the federal Department of Health and Family Services.
5 iii Abstract Private health insurance is an important source of health funding in Australia and interest in identifying who has private health insurance has grown since the mid-1980s. The first part of the study analyses data from the national health survey to examine the distribution of private health insurance across different subpopulations in Australia. The second part of the study identifies the important determinants of private health insurance. In doing so, it was found that there were substantial differences not only in who has private health insurance, but also in the type of insurance purchased, across a broad range of analysis groups identified by income, family type, age, health services used, health status, health risk factors, ethnicity and region of residence.
6 iv Author note Deborah Schofield was a Research Fellow at the National Centre for Social and Economic Modelling. She now works for the Australian Institute of Health and Welfare, Canberra. Acknowledgments The author would like to thank Professor Dick Scotton for refereeing the paper. Thanks also go to Richard Percival, Jonathan Baldry, Geoff Sims and Anthony King for providing helpful comments on an earlier draft and to Ralph Lattimore for his assistance in preparing a spreadsheet version of the author s model in chapter 5. General caveat NATSEM research findings are generally based on estimated characteristics of the population. Such estimates are usually derived from the application of microsimulation modelling techniques to microdata based on sample surveys. These estimates may be different from the actual characteristics of the population because of sampling and nonsampling errors in the microdata and because of the assumptions underlying the modelling techniques. The microdata do not contain any information that enables identification of the individuals or families to which they refer.
7 v Contents Abstract Author note Acknowledgments General caveat... iii...iv...iv...iv 1 Introduction Private health insurance in Australia Methodology The data source Variables used in the analysis Distribution of private health insurance Distribution of private health insurance by type of private health insurance Distribution of single rate private health insurance among families Determinants of private health insurance Multivariate models of private health insurance Identifying significant determinants of private health insurance Using scenarios to examine the probability of insurance Ranking variables in order of importance within the models Summary Appendix A Coefficients, significance levels and standard errors for logit regressions References... 54
8 1 1 Introduction This paper describes an analysis of the distribution of private health insurance and of which characteristics are most important in determining who had private health insurance in Australia in The study uses data from the national health survey (NHS) (ABS 1990). The NHS included information on private health insurance, expenditure on private health insurance, information on health and health service use, and a wide range of socioeconomic characteristics. Knowledge of the distribution and determinants of private health insurance is crucial for planning public health service delivery and funding, and for analysing existing or new private health insurance policy, particularly as the public and private health systems are so interdependent (Cameron et al. 1988). Since the introduction in 1984 of Medicare, a universal public insurance system, there has been a quite rapid shift in the socioeconomic characteristics of Australians who have private health insurance and, accordingly, interest in the distribution of health insurance has increased (Private Insurance Taskforce 1993; Schofield et al. 1996; Willcox 1991). There have been several studies that have included an analysis of the distribution of private health insurance (ABS 1995a; Burrows, Brown and Gruskin 1993; Hopkins and Kidd 1993). However, these have generally limited their analysis to whether a person (or family) is insured. This study extends previous analyses of the distribution of private health insurance by including a specific analysis of the type of health insurance held by contributors. It also includes analysis of a wider range of variables than earlier studies did including, for example, the use of health services, ethnicity and region of residence. In addition, there is an examination of the characteristics of families who choose to insure only one family member. There have also been several Australian studies reporting on the determinants of private health insurance. However, some of these studies are limited by their use of pre-medicare data (Cameron et al. 1988; Cameron and Trivedi 1991; Ngui, Burrows and Brown 1989), their small selection of variables (Burrows et al. 1993; Willcox 1991) or their reliance on a relatively small sample (Burrows et al. 1993).
9 2 Discussion Paper No. 17 Hopkins and Kidd (1993) completed a more comprehensive study of the determinants of private health insurance using post-medicare data. They confirmed that economic, demographic and health status variables were important predictors of who held private health insurance. In addition, they established that a further demographic variable (education), the use of some health services (hospitalisation and doctor visits) and a single health risk factor (smoking) were also important determinants of private health insurance. More recently, the Australian Bureau of Statistics (ABS 1995a) undertook a larger study which, in addition to the variables reported in studies such as that of Hopkins and Kidd, found that health concession card status as well as several interaction terms state of residence and income, state of residence and health concession card status, age and health concession card status, and income and health concession card status were significant predictors of private health insurance. The ABS identified age and income as being strongly related to the likelihood of having private health insurance, while health status was found to be less significant. This study adds to the earlier work on the determinants of private health insurance by providing an analysis of a considerable number of determinants of private health insurance that have not previously been reported. These are measures of a broader range of health service usage and additional health risk factors, demographic variables and interaction terms. In addition, it identifies determinants specifically associated with various types of insurance. The importance of analysing the type of private health insurance purchased was identified by Hopkins and Kidd who observed: It is possible that the determinants of the decision to purchase private health insurance varies across the type of policy. However, Hopkins and Kidd were unable to distinguish between different types of private health insurance in their study because of the structure of their data.
10 The Distribution and Determinants of Private Health Insurance in Australia, Private health insurance in Australia Since 1984, Medicare has provided universal public health insurance through which the cost of medical services and public hospital treatment is subsidised. Private health insurance is available in Australia as a supplement to Medicare rather than as an alternative. Although the introduction of Medicare has seen a rapid decline in the number of Australians with private health insurance from 63.9 per cent in 1983 to 43.0 per cent in 1992 (ABS 1995a, p. 2) private health insurance remains an important source of health funding, covering 39 per cent of all hospital admissions in (Private Insurance Taskforce 1993, p. 1). In , 12.2 per cent of all current health expenditure was financed from private health insurance contributions (Australian Institute of Health and Welfare 1995). While there are many variations on the types of private health insurance (for example, cheaper policies for people who wish to limit their insurance cover by excluding specific treatments such as hip replacements and policies that reduce the premium by charging an excess when a claim is made), there are only three broad types of private health insurance basic hospital insurance, supplementary hospital insurance and ancillary insurance. Basic hospital insurance covers the full cost of shared ward accommodation as a private patient in a public hospital. It also covers part of the fee for private hospital accommodation and the 25 per cent gap between Medicare benefits and the schedule fee for medical services. Private patients with basic hospital insurance being treated in either a private or public hospital can choose their treating doctor. Supplementary hospital insurance provides all the benefits of basic hospital cover plus higher benefits for private hospital accommodation and covers additional private hospital costs (such as theatres, intensive care units and labour wards). Private health insurance companies are able to choose which additional services and benefits they offer with supplementary hospital insurance.
11 4 Discussion Paper No. 17 Ancillary insurance contributes towards the cost of services not covered by Medicare such as dentistry, optical, chiropractic, podiatry, home nursing, speech therapy, physiotherapy, clinical psychology and home nursing. Ancillary insurance can be purchased with hospital insurance or separately. Government regulations require that health insurance costs are governed by community rating, such that health funds must offer any of their policy options at the same rate irrespective of factors that would be expected to influence health service use such as age, sex or health status (Willcox 1991, p. 12). 3 Methodology 3.1 The data source The source of data used in this study is the national health survey conducted by the Australian Bureau of Statistics (ABS 1990). The NHS is a particularly useful data source for analysing the determinants of private health insurance because of its comparatively large size (about persons) and the large number of important socioeconomic, health insurance, health risk and health service usage variables it contains. The NHS is available as a unit record dataset that is, it provides a single record containing information about each respondent to the survey. Each record has a weight attached, indicating how many similar Australians (of the same age, sex and state of residence) the record represents. The information in the survey was obtained from residents of private dwellings (houses, flats, etc.) and non-private dwellings (hotels, motels, caravan parks, etc.). Households were selected from all states and territories. The only exclusions were non-australian diplomatic personnel, members of non-australian defence forces, persons holidaying in Australia, students at boarding schools and institutionalised persons (ABS 1993, p. 125).
12 The Distribution and Determinants of Private Health Insurance in Australia, Variables used in the analysis The NHS provides more than four hundred variables describing the health insurance status, health status, health service use, health risk factors and socioeconomic and demographic characteristics of respondents. Most of the characteristics selected for the distributional analysis and models of the determinants of private health insurance were directly available as variables from the NHS. Some, however, had to be derived from other NHS variables. These are now described. Family income The definition of income provided in the NHS is annual gross income. Gross income includes regular income from any source including wages and earnings, investments, compensation payments and cash payments such social security payments. However, the finances available to individuals to purchase private health insurance are generally determined by family 1 rather than individual income. Therefore, family rather than individual income was used in this study, with family income being defined as the sum of the income of both adults for couples with or without children. 2 Health concession card The definition of a health concession card that was adopted was based on whether an individual was covered by a Social Security health concession card and/or a Veteran s Affairs health concession card. In accordance with the way health concession cards apply in practice, a 1 For the purposes of this study a family was defined as an income unit. An income unit is defined by the ABS as one person, or a group of related persons, within a household, whose command over income is shared (ABS 1995b, pp. 26 7) that is, a single person, a couple (married or de facto) with or without dependent children, or a sole parent and dependent children. Family units differ from income units in that nondependent children (who are employed or on social security benefits, for example) form their own independent income unit. 2 Incomes in the NHS were in $5000 ranges. In calculating family income, the midpoint of the income range was used.
13 6 Discussion Paper No. 17 health concession card reported by one member of the family in the survey was considered to cover all family members (that is, partner and dependent children). Private health insurance The analysis of private health insurance for this study was undertaken at the person level. However, in the NHS, family private health insurance was sometimes reported by only one or two family members (for example, the two parents but not the children). In these cases, all members of the family were considered to be insured. Occupation The definition of occupation for this study was generally based on occupation as specified in the NHS. However, one of the occupation categories combined people in the armed forces, the unemployed, people out of the labour force and the group for whom an occupation was not applicable (children and the retired). Accordingly, analysis by occupation for this category was combined with information on labour force status to separately identify the unemployed and those in the armed forces and to exclude children and persons not in the labour force. Pharmaceuticals used The use of pharmaceuticals was estimated from the total number of medications reported in the two weeks prior to interview for the NHS. Pharmaceuticals in the survey were categorised as vitamins, cough medicines, medication for allergies, skin treatments, laxatives, heart medication, sleeping tablets, pain killers, tranquillisers, and other medications. Use of more than one type of medication was, however, recorded only for vitamins, sleeping tablets, pain killers and tranquillisers. Smoking The incidence of smoking was based on whether respondents to the NHS smoked cigarettes, a pipe or a cigar at the time of the survey.
14 The Distribution and Determinants of Private Health Insurance in Australia, Alcohol consumption The measure of alcohol consumption was based on the number of millilitres of alcohol consumed in the week prior to the interview for the NHS. Once these additional variables had been derived, the resulting data were used to undertake an analysis of the distribution of private health insurance (chapter 4) and an examination of the determinants of private health insurance (chapter 5). 4 Distribution of private health insurance The distribution of private health insurance is examined to identify which Australians have private health insurance in the 1990s. The examination is in two parts. In the first part, the analysis considers the distribution of private health insurance by the three major insurance categories hospital and ancillary insurance, hospital-only insurance and ancillary-only insurance. It was considered important to separate people with only one type of insurance from those with the more comprehensive hospital and ancillary insurance as it was anticipated that the incidence of the more comprehensive cover would be associated with higher income. In addition, the purchase of only one type of insurance was seen as a potentially useful indicator of the perceived need for the services covered by the insurance type. The results of this analysis were later also used to suggest which characteristics might be significant determinants of private health insurance. The second part focuses specifically on the distribution of the choice to insure only a single family member within families of two or more persons. It is important to focus on this subpopulation to determine how the insured family member differs from the uninsured family members, and how families who choose to insure only one member differ from other families where the whole family is either insured or uninsured.
15 8 Discussion Paper No Distribution of private health insurance by type of private health insurance Private health insurance by income Analysis of private health insurance type by income found that the proportion of individuals without private health insurance decreased as incomes increased. About 76 per cent of people from families with incomes of $ to $ a year were uninsured compared with 16 per cent of people from families with incomes of $ or more a year (table 1). 3 These findings are similar to those reported by other researchers (ABS 1995a; Cameron and Trivedi 1991; Hopkins and Kidd 1993). The probability of individuals reporting the top level of health insurance cover that is, insurance for both hospital and ancillary services also increased with income. Individuals from high income families were three times as likely to have hospital and ancillary insurance as those with the lowest incomes. The proportions of families with hospital-only or ancillary-only insurance showed less variation with income (12 per Table 1 Individuals by type of private health insurance and by family income, Australia, Family income Uninsured Ancillary-only Hospital-only Hospital and ancillary Total % % % % % $ $ $ $ $ $ $ $ or more Source: ABS (1990). 3 Incomes are for The lowest income range presents some difficulties for interpreting health insurance trends as it is composed of both low income earners as well as families whose principal income source is a private business. Private business income for a family might have been zero or negative in the reported financial year yet the business may have performed well in other years and allowed the accumulation of assets.
16 The Distribution and Determinants of Private Health Insurance in Australia, cent of families with incomes of less than $ a year and 13 per cent with incomes of more than $70 000). However, when only individuals with private health insurance are considered (table 2), about 27 per cent of insured individuals with family incomes of less than $ a year had hospital-only insurance, compared with about 13 per cent for individuals with family incomes of more than $ a year. This finding indicates that insured individuals with low family incomes more often choose cheaper health insurance. Table 2 Insured individuals with hospitalonly private health insurance, by family income, Australia, Family income Hospital-only % $ $ $ $ $ $ $ $ or more 12.7 Source: ABS (1990). Measures that are closely related to income produce similar results. For example, when an analysis is undertaken by equivalent family income 4 individuals with the highest equivalent family incomes were substantially more likely to be insured than those on lower incomes. The major difference was that, after adjusting for income, about 90 per cent of families in the income group with the lowest rate of insurance (that is, families in the second decile of equivalent income) were reported as uninsured. By contrast, when non-equivalent income measures had been used, about 75 per cent of the income group with the lowest rate of insurance were reported as uninsured (table 1). 4 The equivalent income measure in the NHS ranked family income by deciles after adjusting family income to account for the size of the family. Equivalent income was defined on the basis of Henderson simplified equivalence scales (Mathers 1994).
17 10 Discussion Paper No. 17 Similarly, an analysis by access to the benefits of a health concession card indicated that about 70 per cent of card holders, who have low incomes, were uninsured, compared with 40 per cent of people who did not have health concession cards. When the source of income was considered, individuals whose main source of income was a pension or benefit reported the lowest incidence of private health insurance (65 per cent uninsured) (table 3). (This outcome is to be expected as this group also had the lowest average income.) Notably, people who derived their income primarily from their own business reported a higher incidence of private health insurance than those whose main income source was wages and salaries. People who have their own business may regard a health crisis as posing a greater financial risk since they may not only face considerable health care costs, but are also likely to lose income for the period they are unable to work. Individuals whose primary income source was superannuation or investments reported the highest incidence of private health insurance, with almost 70 per cent of this group insured. (This group also reported the highest proportion of individuals choosing hospital-only insurance.) This is an important finding as about 75 per cent of people with superannuation as their main source of income were aged 60 years or more. As a result, with an increasing number of the aged relying on superannuation rather than the age pension as their main income source over Table 3 Individuals by type of private health insurance and by main source of family income, Australia, Main source of family income Uninsured Ancillary-only Hospital-only Hospital and ancillary Total % % % % % Pension or benefit Wages and salaries Own business Superannuation Investment Source: ABS (1990).
18 The Distribution and Determinants of Private Health Insurance in Australia, the next years, it might be expected that health insurance coverage among the aged will increase. The incidence of private health insurance was also found to vary considerably with occupation and labour force status. This is to be expected as average income is closely related to occupation. Professionals and managers reported the highest incidence of private health insurance (73 per cent and 71 per cent respectively) declining to less than 50 per cent for trades people and labourers (table 4). The lowest incidence of private health insurance was among the unemployed, with only 27 per cent of this group insured. This finding would suggest that the rapid growth in the ranks of the unemployed in the past decade with the number of recipients of unemployment benefits rising from about in 1982 to a peak of approximately in 1993 (Department of Social Security 1993) might well have had a major impact on the decline in the total number of Australians with private health insurance. It is also possible that if the longer term unemployed find that Medicare provides adequate health care they may be less inclined to take up private health insurance when they are re-employed. Table 4 Working age adults by type of private health insurance and by occupation and labour force status, Australia, Occupation and labour force status Uninsured Ancillary-only Hospital-only Hospital and ancillary Total % % % % % In paid employment Professional Manager Paraprofessional Armed services Clerical Sales Plant operator/driver Trades Labourer Not in paid employment Out of the labour force Unemployed Source: ABS (1990).
19 12 Discussion Paper No. 17 Private health insurance by family type Individuals from a family consisting of a couple with children reported the highest incidence of private health insurance 61 per cent (table 5). Individuals from sole parent families reported the lowest incidence of private health insurance 24 per cent. These findings are similar to those reported by the ABS (1995a). The low incidence of private health insurance among sole parent families compared with couples with children is probably determined, at least in part, by the difference in average incomes between the two family types. However, even accounting for income, there was still a considerable difference in the incidence of private health insurance between the two family types. For example, for families with incomes under $ a year, about 60 per cent of individuals from couple with children families reported being insured, compared with only about 20 per cent of individuals from sole parent families. Single people reported an incidence of private health insurance (38 per cent) that was substantially lower than for couple families with or without children. However, their incidence of insurance was still substantially higher than that of individuals from sole parent families. Interestingly, while couples without children reported an incidence of insurance similar to couples with children (60 per cent and 61 per cent respectively), they reported a higher incidence of hospital-only insurance (13 per cent compared with 8 per cent of couples with children). Table 5 Individuals by type of private health insurance and by family type, Australia, Family type Uninsured Ancillary-only Hospital-only Hospital and ancillary Total % % % % % Couple with children Couple without children Sole parent Single Source: ABS (1990).
20 The Distribution and Determinants of Private Health Insurance in Australia, Private health insurance by age The age distribution of private health insurance has become a key area of interest, as the ageing of the population and a reduction in the number of younger people with private health insurance have resulted in an increasing pool of insured who are 60 years of age or over increasing from 13 per cent in 1983 to 22 per cent in 1990 (Willcox 1991). Despite concerns about the growing pool of elderly insured, it is still the group aged years who report the highest incidence of private health insurance about 60 per cent insured (table 6). In fact, it was the age group of 80 years and over who reported the lowest incidence of private health insurance 38 per cent insured. An examination of the distribution of private health insurance by age revealed some interesting results. About 55 per cent of children aged 0 14 years were covered by health insurance. People aged years, by contrast, had the second lowest incidence of private health insurance, with 40 per cent of year olds reported as insured. The incidence of Table 6 Individuals by type of private health insurance and by age, Australia, Age Uninsured Ancillary-only Hospital-only Hospital and ancillary Total years % % % % % or more Source: ABS (1990).