1) The development of guidelines for the construction and calculation of health expectancies with a view to European harmonization of concepts, data collection, and calculation methods.
2) To provide a European data base on health expectancies which may be put at the disposition of individuals and organizations involved in health research and development programmes.
3) To edit a reference document describing concepts, questionnaires and calculation methods which may be used as a basis for the further promotion of calculations by other countries both within and outside Europe.
Scientific background : Dramatic increases in life-expectancy constitute perhaps one of the most remarkable advances of the twentieth century. As the year 2000 approaches a further challenge confronts us : Are the additional years gained in life-expectancy spent in good health or in a prolongated state of illness and dependancy ? The recent development of indicators of disability-free life-expectancy have provided a means of addressing this important question, fundamental both for the understanding of the evolution of the health status of populations and for the formulation of government policies directed at the provision of services.
The Action should recommend guidelines for the harmonization of health expectancy calculations in Europe, constitute a central data collection centre, and provide a forum for the discussion of the future use of such information. It is important to note that the proposed European network does not aim to subsidize or initiate new health surveys (this is the responsibility of the NIS and its subsidiary Eurostat). EURO-REVES is designed to promote the exploitation of data presently available and to provide European guidelines for future population studies.
The need to harmonize calculations in order to facilite joint planning of health programmes and for the comparison of the health status of different communities and socio-economic groups within the future Europe is recognized by all participating teams. If the principal objective of social and health systems is not only to prolong life but also to maintain its quality in terms of autonomy and social functioning for as long as possible, then health expectancy comes close in theory to an ideal indicator for monitoring the realisation of health objectives in Europe.
2 - OBJECTIVES : Harmonization of health expectancy calculations in Europe
At a general level three broad aims may be differentiated :
1) The development of guidelines for the construction and calculation of health expectancies with a view to European harmonization of concepts, data collection, and calculation methods.
2) To provide a European data base on health expectancies from the calculations made by members of the Concerted Action teams which may be put at the disposition of individuals and organizations involved in health research and development programmes.
3) To edit a reference document describing concepts, questionnaires and calculation methods which may be used as a basis for the further promotion of calculations by other countries both within and outside Europe.
More specifically, these aims imply the achievement of the following objectives :
a) The definition of indicators and their policy framework (that is, their future application) ;
b) Conceptual harmonization based upon the WHO International Classification of Impairments, Disabilities, and Handicaps ;
c) Selection of the Impairments, Disabilities, and Handicaps to be aggretated with mortality ; equal attention shall being paid to the health of children, adults and elderly people ; to mental as well as to physical impairments ;
d) Selection of the health expectancy calculation method (Sullivan's method, double decrement table, multi-states life table, Markov process) ;
e) Decision as to the type of survey suited to the collection of health expectancy data given the restrictions of a) to d). For example, simple transversal survey, repeated passages survey or longitudinal study for specific hypotheses ;
f) Formulation of "standard" questions (wording, translation, validation, cultural cross-validation), in cooperation with the "Consultations to Develop Common Methods and Instruments for Health Interview Surveys" organised by the Netherlands Central Bureau of Statistics under the aegis of the WHO, the "Committee of Experts for the Application of the WHO International Classification of Impairments, Disabilities, and Handicaps", Council of Europe, the UN statistical office initiatives to improve the disability statistics, and the "REVES Committee on Conceptual Harmonization".
g) The provision by each member team of suitable health expectancy data from presently existing sources for at least one of the proposed indicators for the constitution of the data base and including the registry of causes of ill-health. For this reason only teams already involved in health expectancy calculations may become contracting members. Euro-REVES does not intend to initiate or finance new health surveys.
h) Provision of guidelines relating to survey sample size to ensure adequate representation of countries, regions, age and social groups making up the European population.
i) The drafting of a European Standard with specific conditions for the carrying out of national health surveys ensuring adequate inter-European comparisons.
3 - SCIENTIFIC AND TECHNICAL DESCRIPTION
(including distribution of the tasks)
Scientific background : Dramatic increases in life-expectancy constitute perhaps one of the most remarkable advances of the twentieth century. As the year 2000 approaches a further challenge confronts us - increasing life-expectancy in good health. This goal raises the important issue of quality of life. Over the past twenty years researchers in such varied fields as epidemiology, demography, clinical medicine, psychiatry, statistics and health planning have raised the questions : are the additional years gained in life-expectancy spent in good health or in a prolonged state of illness and dependancy ? (Fries, 1989 ; Kramer, 1980). Tho what end the prolongation of life if this is to be accompagnied by increases in severe mental and physical disability ? The recent development of indicators of disability-free life-expectancy have provided a means of addressing these important questions, fundamental both for the understanding of the evolution of the health status of populations (Manton, 1982 ; Robine et al., 1992 in press), and forthe formulation of government policies directed at the provision of services (WHO, 1984 ; Verbrugge, 1989 ; Olshansky et al., 1991 ; Van de Water, 1991).
The indicators of health expectancy will undoubtedly play an important future role in terms of health information, planning, management and adjustment of care systems : measuring evolution and inequities and permitting international comparisons.
Disability-free life expectancy is an indicator of population health status derived from mortality and disability estimates which essentially explores the question of whether observed increases in life-expectancy are also accompanied by decreases in morbidity. Interest in the relationship between mortality and morbidity grew out of speculation concerning the effects of the unpredicted drop in mortality rates observed in the elderly over the past fifteen years. A fundamental question posed by demographers and epidemiologists in response to this observation was whether this drop was prejudicial to the quality of life, such that persons having escaped death through for example,cardiovascular desease, would go on to live in a state of chronic ill-health (Fuch, 1984). While the notion of Disability-Free Life-Expectancy was proposed by Sanders as early as 1964, it was not until the early 1970's that Sullivan developed a simple method for its estimation. His method involves the calculation of the total number of years lived by the population at different ages in relation to the number of years lived without disability as deduced from prevalence rates from cross-sectional health surveys.
From the early 1970's up until 1986 at least a dozen such calculations appeared, emanating from Canada, the United States, France and Japan (Robine, 1986). In 1983, the first period calculations were carried out, by Latz et al, using double-decrement life-tables. These early calculations suggest that gains in life-expectancy appear to be largely lost in disability, thus supporting Kramer's fears that the ageing of the population may result in a "pandemic of mental disorders and associated chronic diseases". Such conclusions are, however, premature and further research is required to clarify these findings and correct for possible biases in the methods used.
While the potential usefulness of health expectancy calculations such as Disability-Free Life-Expectancy, as posed to simple mortality statistics, for European comparisons of health status and allocation of resources is reasonably evident, a number of difficulties relating to the actual calculation of health expectancies are still to be resolved. The most compeling is the question of the reliability of measures. While there has been considerable consistency between European studies with regard to the mathematical methods used to calculate disability-free life-expectancy (Bebbington, 1988, 1991 ; Bronnum-Hansen, 1990 ; Egidi, 1987 ; Gispert et al, 1991 ; Gutiérez Fisac et al, 1991 ; Petterson, 1991 ; Robine et al, 1986 ; Spuhler et al, 1991 ; Van Ginneken et al, 1991) there are nonetheless significant differences with regard to the definitions and measures of disability employed (Robine et al, 1991). As the standardization of physical disability measures has been largely realized in the last fifteen years with the development of the concepts of impairment, disability and handicap (WHO/ICIDH, 1980) more reliable instruments for the measurement of physical incapacity are now available.
The feasability of developing other indicators, notably life-expectancy without mental disability (Ritchie, 1992 in press) are also currently being explored. In particular the question of whether the calculation of life-expectancy without cognitive deterioration can be accurately estimated is of increasing interest given the public health problems raised by the predicted increase in the prevalence of senile dementia. Recent developments in the formulation of internationally acceptable diagnostic algorithms for senile dementia (American Psychiatric Association, 1980 ; McKhann et al., 1984 ; World Health Organisation, 1978) have now made such a calculation possible within a European context (Ritchie et al., 1992).
An international network (REVES, the French acronym for Network on Health Expectancy and the Disability Process) was established in 1989 in order to address problems relating to the development of standardized international measures of health expectancies. The network did not aim to initiate health surveys but rather to exploit data presently available for the calculation of health expectancies. An important point which has been raised by the network is the notion of reversibility or permanence of ill-health (especially disability). This question has not been properly examined to date due to the common use of Sullivan's method which side-steps the issue by directly observing prevalence (in itself a function of duration on ill-health). Future calculations using period data should, however, take up this issue (Rogers et al., 1989 ; Brouard et al., 1992). REVES has succeeded over the past two years, through international meetings and over 100 working papers, in assembling an almost complete list of the differences between studies which have impeded cross-national comparisons. The final aim of this group is to provide internationally acceptable directives which may finally permit the development of comparable estimates.
Within REVES, the European teams have shown considerable similarity in their method of calculation and analysis of the disability process (Minaire, 1991). This has quite understandably led to early attempts to coordinate and compare health ezxpectancy studies within a European context. Unfortunately, however, although disability-free life-expectancy values are now available for France, Germany, Italy, the Netherlands, Spain, the United Kingdom, Sweden, Switzerland and Denmark, it is impossible at the present time to make meaningful comparisons due to the very great differences in the questions used and the research designs.
The aim of the present proposal for a Concerted Action is to formalize these early initiatives by the European group. More specifically, the Action should recommend guidelines for the harmonization of health expectancy calculations in Europe, constitute a central data collection centre, and provide a forum for the discussion of the future use of such information. It is important to note that the proposed European network, like REVES International, does not aim to subsidize or initiate new health surveys (this is the responsibility of the NIS and its subsidiary Eurostat) ; EURO-REVES is designed to promote the exploitation of data presently available and to provide European guidelines for future population studies.
This initiative is based on two guiding principles : (1) that this be a stage process in which agreement is required at the first level before proceeding to the next, and (2) that it may be necessary in the interests of European comparability to strike a compromise between methods which are costly but theoretically ideal (the construction of multi-state tables based on follow-up studies or strict adherence to the content of questions) with what is practicable.
PROPOSAL METHODOLOGY : The objectives of the Concerted Action will be met through annual general meetings, committee work between general meetings and by data organization at a national level. The provision of data will be the responsibility of the countries involved. As harmonization requires reflection on both general topics common to all health expectancy calculations, and also specific expertise (for example psychiatric assessment, the development of mathematical models) the work of the network is divided for practical purposes into three committees :
Policy relevance and conceptual harmonization
This group will be responsible for the definition of indicators and their policy targets, conceptual harmonization, the choice of instruments and survey methods.
Research design and calculation methods
This group will provide recommendations on sampling, repeat survey methods, and calculation methods.
Mental health indicators
This group will select appropriate measures and case-finding procedures for the calculation of life-expectancy without mental impairment.
All member teams wil elect at least one member to participate in the first committee. The members of the other two committees will be appointed by the committee coordinators.
It is envisaged that the Concerted Action should continue over a period of four years from January 1994 to December 1997. The work of the group will be organized around 5 central meetings (March 1994 ; September 1994 ; September 1995 ; September 1996 ; September 1997. Each of these meetings will take place in a different country of the Community. It is presently envisaged that these countries will be France, Denmark, Holland, Italy and the United Kingdom. Each team will have a participating member in the first sub-committee (conceptual harmonization) and each country will be expected to review the recommendations of all three sub-committees. A working paper should be prepared by each team for each of the five meetings.
Each of the five meetings will be organized around a specific theme, tese being :
Meeting 1. Discussion of the special interests of a European group and uses of
health expectancy calculations within the community (France, March,
1994).
Meeting 2. Policy relevance and conceptual harmonization (Denmark, Septembe,r
1994).
Meeting 3. Research desing (Holland, September, 1995).
Meeting 4. Mental health indicators (Italy, September, 1996).
Meeting 5. Presentation of committee reports and general recommendations (United
Kingdom, September, 1997).
The committee coordinators will convene parallel meetings according to their own needs (these meetings should be at least annual and no more than two per year may be sponsored by the Action). The distribution of work in the sub-committees, the fixing of themes, meetings and working papers will be the responsibility of the committee coordinators. Each Committee coordinator will be responsible for the organization of the general meeting relating to the committee's work.
The coordinator of the network will undertake the compilation of the general recommendations of the three sub-committees and the working papers which will form the basis of a document "European Standards for the Calculation of Health Expectancies". The task of writing and editing these documents will be divided amongst participants. The translation of the document into the languages of the Community countries will be the responsibility of the participating teams.
In parallel with these meetings participating teams will be expected to provide data on health expectancy suitable for cross-national comparisons from their own country using at least one, and preferrably more than one, of the health indicators defined by the three specialist committees. The establishment of a central data bank will be the responsibility of the network coordinator. Participating teams will be required to forward data in ASCII format to the coordinator who will ensure computerized storage and safe-guards. The data will not include any personal reference which would permit the association of results with a particular individual. The transfer of this type of information does not require permission from an ethical committee in any of the member countries. A meta-analysis of the data will be initiated by the network coordinator in cooperation with the specialist committee on calculation methods.