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The prevalence of chronic disease in children in Finland
Ptt.bL HIth, Lon~L (1978) 92. 272-2'78
The Prevalence of Chronic Disease in Children in Finland Hannu Vuori* M.D.. Ph.D., M.A.
Professor and Chairman. Department of Community HeaRh. University of Kuopio, 70101 Kuopio/o, Fin/and Heika Urponen M.P.Sc.
C/Ti/dren's Hospita/, University of Turku. 20520 Turku 52. Finland and Tuomas Peitonen M.D
Professor of Pediatrics. C~Tdren's HospRa/, University of Turku, Fin/and To stud)' the assumption that chronic diseases in children are more prevalent than generally expected, 400 randomly selected Finnish public health nurses were requested to report fine diagnosis, names, ages and sex of all chronically sick children they were aware of. The informants reported 8321 chronically ~ick children (excluding diseases of the sense organs), 51% of them being boys and 49~o girls. The total prevalence 'was 34.8 per lO00 Children under :16 years of age or 38,000 chronically sick children in /lie entire country. The prevalence was highest in the northern and eastern provinces. The two largest groups of diseases were congenital m~ffformations (35Y/o) and allergic diseases (25 ~/o). All the other groups accounted for less than I01'o. o/ The age-st~cific prevalence of congenital diseases and malformations rapidly decreased with advancing age whereas that of endocrinological diseases, psychiatric conditions and sequalea of injuries slightly increased. The study yielded a higher estimate of the prevalence of chronic diseases in children than any previous study in Finland, It also indicated that where the prevalence is highest there the health services are in shortest supply.
Introduction The child as an object a n d beneficiary of social services has lately been subject t o lively discussion in Finland. The h u m a n rights of children have been emphasized; bills,concerning the organization o f day care have been introduced through parliament; the low birth rate has caused concern, so family allowances have been increased; free health services have been extended to the students o f vocational schools. In this context, it has been ,claimed that one group o f children has been forgotten: children with chronic diseases. It has also been maintained that chronic diseases are more prevalent in children than revealed by the official statistics and that many chronically sick children d o not receive adequate care although their condition is known to their parents and even to health personnel. They are thus in need o f health and social services and should be taken into account in planning these services. *Present address: National Center for Health Services Research, Department of Health, Education and Welfare, Office of the Assistant Secretary for Heallh, Hyaatsville. Md 20782, U.S.A. 0038-3506,'78,/060272 +07 $01.00/0
c~ 1978 The Society':of Community Medicine
Chrmtic disease h~ chiMren
273
To examine t,he claim that chronic diseases in children may constitute a pocket o f neglected morbidity, a study with the following aims was launched in Finland in t97I : (1) to ascertain the prevalence of chronic diseases in children in domiciliary care by age and disear~e groups; (2) to study the social consequences of chronic diseases in children; (3) to estimate the need of care and possibilities for rehabilitation o f children with chronic diseases. This report covers the first objective o f the study. Material and Methods
Defin#ion of chronic ithwss From the l I disease categories shown in Table 1, 43 diseases or conditions that are either by origin (e.g. endocrinological diseases, congenital malformations).or by experience (e,g, asthma, tuberculosis) chronic and occur in childhood were included in this study. Children having any of these diagnoses were included in the ,sample if their illness had lasted at least for 3 months and was expected to continue further at the time of the study, ,o/ TABLE t. The number of observed cases, the relalive share (/o), Ihe prevalence (per 1000 children under 16 years o f age) and the estimate of the 1olat number of chronically sick children in Finland, by disease categories
Diagnosis
Number of observations
Relalive share (~)
Prevalence in Finland (per 1000)
l. Allergic diseases 2088 25 2. Tuberculosis 60 1 3. Endocr/nokrgica| diseases 458 5 4o Congenita'l diseases and malformalions 2877 35 5, Sequelae of injuries ,220 3 6. Diseases of Ihe nervous system 598 7 7, Psyc~/iatric ,diseases 5:14 6 8. Diseases o f ~he :urinary syslem 345 4 9. Blood diseases 202 2 10. Other chronic diseases 959 12 -(1 I. Diseases 'of the sense organs .excluded from the -presentation .of the results) Total 8321 100
To~al number of chronically sick children
8-7 0-3 1-9 12-0 0.9 2-5 2.1 1-4 0-8 4-0
9700 300 2100 13,000 1000 2500 2500 1600 900 4400
34"8
.38,500
Informants Public health nurses reporte d the.data. Public health nurses are registered nurses who have received one year of postgraduate training in preventive medicine and public health. The Finnish communes (the smallest independent local administrative unit) have a statutory obligation to hire public health nurses to carry out activities primarily pertaining to maternity and child health and preventive medicine. The public heaRh nurses cover the entire child population o f a commune and maintain comprehensive and up-to-date records o f all children in their charge.iThey are also familiar with the livin~ conditions o f the children, The informants of the study were selected by means o f a txvo'sta~e probability sample, First 280 communes were selected using sampling with probability proportional to the size o f the communes. The Provincia:l Health Officers provided the names of all public
274
H. Vuori, 1t. Urponen and "1".Peltonen
health nurses working ]n the selected communes. From these ~ames, one out of four was randomly picked. This stage yielded 400 public health nurses. Out of these, 374 (94,%) consented to participating.
Study population The public health nurses were asked to report, using a mailed questionnaire, the names, ages, sex, parents and diagnosis of chronically sick children under 16 years o f age in their district they were aware of and whose illness corresponded with the criteria stated above. In the questionnaire, all the diagnoses included in the study were listed and the public heatth nurses ticked the appropriate diagnosis 'for each reported child. To enable the computation of the prevalence rates, the :informants also reported the total number of children under 16 years of age in their district. The latest (1970) census data of the communes were used to obtain the age distribution of these children.
Lhnimtions o f the stud), The material represents only the non-institutionalized child population with a manifest chronical illness known to the public health nurses. The definition of chronic illness used in this study emphasizes the social aspects of chronic diseases (long duration, consequences) at the expense o f a medically clearly defined diagnosis. This emphasis was appropriate in the light of the objectives of the subsequent phases of the study but constitutes a limitation in a prevalence study.
Size of the sample Altogether 8321 chronically sick children were reported, 51 ~ of them being boys and 49 ~ girls. Results To provide an overall view of the magnitude of the problem, as seen from the social point of view, the total prevalence and the distribution of the broad disease categories is being presented. D~ta on diseases of the sense organs that were originally collected are excluded from all results, as this group contained a large number o f poorly defined refraction errors.
The ,total preralence The total prevalence o f chronic diseases was 34-9 per 1000 children under 16 years of age. The morbidity was highest on one hand in Ahvenanmaa (the archipelago in .the Baltic Sea between Sweden and Finland) and on the other hand in the predominantly rural, scarcely 'populated and relatively under developed northern and eastern provinces with exception of the province of Pohjois-Karjala. The estimated number of chronically sick children, .as defined in this study, was 38,500. Some of fhe children had several chronic diseases: 7-5% had itwo and 1 ~/o,three or more diseases.
Prevalence by disease categories Table I gives the number of observed cases, the relative share (~(;), the prevalence and an estimate of the total number of cases in Finland, by disease categories. The emerging picture is clear: Congenital diseases and malformations ( 3 5 % ) a n d allergic diseases (25%) were by far the two largest groups. All the other groups accounted t'or less than 10~ each. The
Chronic disease in children
275
relative importance of various diseases and their combined total prevalence in different age groups is s~hown in Figure 1. The total prevalence more than doubles when moving from the first five-year group and then remains stab Je. The most conspicuous finding with regard to the disease groups was the rapid decrease of the share of congenital diseases and malformations during the first years of life. The prevalence of endocrinological diseases, psychiatric conditions and sequalae of injuries slightly increased and that of blood diseases decreased with advancing age. The share of the other groups was rather constant.
0-4 Per years cent of age ~00%
5 -9 yeors of age
IO-15 years of -age Other chronic diseases
90% Endocrinotogical d iseases 80%
SequalC~e of injuries Psychia~Itic diseases
7'0%
Diseases of nervGus syslems
60%
Oiseoses of the urinar~ .Syslem 50%
40%
At~ergic diseases
30°./0
Blood diseases
20% Conqen.i~ol diseases and malformations
10%
~
~
Total .prevalence per I OO0
Figure I. The relative share (%) of various diseases in different age groups.
Discussion The reliability of the results :of this study can be scrutinized in the light of the melfhods used and their va]idity by comparing them with other known data concerning the morbidity of the Children in Finland.
276
H. ]'5tort, H. UJponen and 7". Peltonen
Reliability of the resu#s The primary source of data was the records of the public health nurses. 'This is on .one hand a limitation: only morbidity known to the nurses was covered. No efforts were made to screen for latent diseases. It can, on the other hand, be argued that as the public health nurse network covers the entire child population and as chronic diseases almost by definition are known to the parents, this source probably provides the best available and indeed quite comprehensive estimate of the magnitude of the problem. It is almost certain that the records of the various healih care institution, s (lecal health centres., hospitals etc.) would have yielded a much lower figure. Finally, Ihe Finnish public health nurses are reno~vned for the high quality of their training a n d work. The sampling procedure used in the study should provide a ,representative geographical coverage. The list o f the public health nurses working in the selected communes was a complete one. The response rate (94.0/o) was high. There may be some bias in the age distribution of the children. In many communes, one public health nurse was responsible -for just .one age group. In other communes the division of ~asks was based not on age but on geographical or administrative areas. The informants did, however, provide .data for all age groups, This means that .in the former group of communes, they had to get part of the .information from the records of other public health nurses. It may be that the data originating from their own records are more reliable than the data emanating .from those o f others.. As there is no reason to believe that the sample was biased in favour of any particular age group, it can, however, be assumed that the possible errors balance each other. The greatest potential source of error is the questionnaire. The information concerning the age and sex o f the children is probably highly reliable, whereas the diagnostic data may be less reliable. This applies especial.|y to some individual diagnosis, not so much to the larger classes o f diagnosis. Some diseases are .clear: e.g. diabetes, congenital heart disease and cleft palate. We believe 'that with regard to such diseases, the material is comprehensive and the diagnosis reIiable. Other diseases are much more vague, e.g. allergic dermatitis, psychiatric conditions and sequalae o f injuries. These conditions may have been systematically under- or over~ reported and there may be errors o f diagnosis. The public health nurses have obviously defined such diseases differently. This was evidenced by comparisons between various communes ,and between nurses working in the same commune. For this reason, no comparisons have been .attempted between towns and rural areas let alone between smaller :geographical units. It can be assumed that the differences of definitions have resulted in under-reporting of minor conditions. As a consequence, the results probably represent a minimum estimate. It should, however, b e emphasized that, in the great majority o f cases, the diagnoses were originally m a d e or later confirmed :by a local physician or some hospital. This ,is especially true o f the more serious diseases. As a consequence, the possible errors of diagnoses primarily concern minor conditions.
Validio, of the resu#s In Finland the data on the prevalence o f chronic diseases of .children are rather scanty. The National Sickness Insurance furnishes certain chronically sick patient groups with free drugs. ~-~n Table 2, the number o f children entitled to free drugs is compared with the estimated number provided b y this study, in certain diseases. The ,data are very concordant. Gylling & Soivio ~ have estimated that in Finland, among :children 0-45 years of age, there are approximately ,I00 cases of cleft palate in each one year cohort which yields a
Chronic disease hr children
277
total of 1500. The estimate of this study is only 900, This difference probably results from the fact that in the older age groups, the condition has been repaired~ The informants have not reported these cases, which is completely in accordance with the objectives of the study and thus partially corroborates the validity o f the results. TABLE2. The number of children entitled to free drugs by lhe Naliorxa] Sickness Insurance and the estimated .number of chronicalb ~ s~ck children based .on the results of this sludy, in certain diseases
Disease Diabeles 'Chronic pyelonephrifis Rheumatoid arthritis Leukemia
Number of children ent~tted Io free drugs (under t5 years of age)
Esti~naled.nut.abet of chrordca'.lly sick children~under 16 3'ears of age)
1569 963 302 77
~600 1200 300 I00
Significance of the results There are two earlier estimates o f the prevalence o f children ,, chroni,~ diseases in ~inland. The Task Force on the Organization ,of Long-term Care s gave 16,000 as the number of chronically sick children. This figure, however, only represents "the t:ip of the iceberg"., the most chronic cases entitled t o various social security benefits. The estimate w a s based on available s,'atistics and studies. The fact that it .included institutionalized children enhances the difference to the present study. V'2itin~nen ~ defined a child's chronical disease ~n the same way as in this study. He also used public health nurses as informants. H e included institutionalized children in his material. When this group is excluded from our .material, our estinaate (38,000) is clearly higher than that of V/i~in~inen (30.900). This study was based on the assumption that Chronic diseases o f chitdren are more common than generally expected and revealed by the official statistics and that the treatment -of these diseases may be partly neglected. The results .of this study corroborate the first part o f the assumption. The latter part o f the assumption is the object of the subsequent phases o f the study. Already o n the basis o f this study, it can be concluded that the prevalence reaches its highest values in areas where medical services are in shortest supply. The product moment (r) and rank order (Kendall's w) correlations between the pediatrician ratio (.per 1000 inhabitants) and the prevalence figures and between the pediatric bed ratio (per I000 inhabitants) and the prevalence :figures by pro'vinces are as follows: /"
W
Pediatrician ratio 0.34 0-28 Pediatric bed ratio .0,48 0-38 This is in accordance with the ubiquitous finding of most studies related to the geographical distribution of adult mobidity: the higher the morbidity, the more meagre the supply o f health services. Acknowledgements The study was supported by grants from the Medical Board of the Finnish Academy, lhe Finnish Cultural Foundation and the Alfred Kordelin Foundation. The investigators also gratefully acknowledge ~the help of the participating public health nurses.
278
I. 2. 3. 4.
H. Vuori, It. Urpo.~ten and 7: Peltonen
References Gylting, U. & Soivio, A. I. (1962L Frequency, morphology and operative mortality in cleft lip and Dalate in FinlaHd. Acta chit. stand. 123, 1-12. Kansanel8kelaitoksen tilastollinen vuosikirja (Yearbook of the National Pensions Inslitule) (1970). Helsinki: The Institute. PitkaaikaishoJtotoimikunnan mietint6 (Report of the Task Force on the Organization of Long-term Care) ('~970). Helsinki: Komiteanmietint6 1970: B 76. V~i~inanen, I. (1972). Pitkfiaikaissairaiden lasten hoidon mrve maassamme 4The need of care of chronically sick children). Sos. l ~ k e t . Aikak L 10, 7.
The Prevalence of Chronic Disease in Children in Finland Hannu Vuori* M.D.. Ph.D., M.A.
Professor and Chairman. Department of Community HeaRh. University of Kuopio, 70101 Kuopio/o, Fin/and Heika Urponen M.P.Sc.
C/Ti/dren's Hospita/, University of Turku. 20520 Turku 52. Finland and Tuomas Peitonen M.D
Professor of Pediatrics. C~Tdren's HospRa/, University of Turku, Fin/and To stud)' the assumption that chronic diseases in children are more prevalent than generally expected, 400 randomly selected Finnish public health nurses were requested to report fine diagnosis, names, ages and sex of all chronically sick children they were aware of. The informants reported 8321 chronically ~ick children (excluding diseases of the sense organs), 51% of them being boys and 49~o girls. The total prevalence 'was 34.8 per lO00 Children under :16 years of age or 38,000 chronically sick children in /lie entire country. The prevalence was highest in the northern and eastern provinces. The two largest groups of diseases were congenital m~ffformations (35Y/o) and allergic diseases (25 ~/o). All the other groups accounted for less than I01'o. o/ The age-st~cific prevalence of congenital diseases and malformations rapidly decreased with advancing age whereas that of endocrinological diseases, psychiatric conditions and sequalea of injuries slightly increased. The study yielded a higher estimate of the prevalence of chronic diseases in children than any previous study in Finland, It also indicated that where the prevalence is highest there the health services are in shortest supply.
Introduction The child as an object a n d beneficiary of social services has lately been subject t o lively discussion in Finland. The h u m a n rights of children have been emphasized; bills,concerning the organization o f day care have been introduced through parliament; the low birth rate has caused concern, so family allowances have been increased; free health services have been extended to the students o f vocational schools. In this context, it has been ,claimed that one group o f children has been forgotten: children with chronic diseases. It has also been maintained that chronic diseases are more prevalent in children than revealed by the official statistics and that many chronically sick children d o not receive adequate care although their condition is known to their parents and even to health personnel. They are thus in need o f health and social services and should be taken into account in planning these services. *Present address: National Center for Health Services Research, Department of Health, Education and Welfare, Office of the Assistant Secretary for Heallh, Hyaatsville. Md 20782, U.S.A. 0038-3506,'78,/060272 +07 $01.00/0
c~ 1978 The Society':of Community Medicine
Chrmtic disease h~ chiMren
273
To examine t,he claim that chronic diseases in children may constitute a pocket o f neglected morbidity, a study with the following aims was launched in Finland in t97I : (1) to ascertain the prevalence of chronic diseases in children in domiciliary care by age and disear~e groups; (2) to study the social consequences of chronic diseases in children; (3) to estimate the need of care and possibilities for rehabilitation o f children with chronic diseases. This report covers the first objective o f the study. Material and Methods
Defin#ion of chronic ithwss From the l I disease categories shown in Table 1, 43 diseases or conditions that are either by origin (e.g. endocrinological diseases, congenital malformations).or by experience (e,g, asthma, tuberculosis) chronic and occur in childhood were included in this study. Children having any of these diagnoses were included in the ,sample if their illness had lasted at least for 3 months and was expected to continue further at the time of the study, ,o/ TABLE t. The number of observed cases, the relalive share (/o), Ihe prevalence (per 1000 children under 16 years o f age) and the estimate of the 1olat number of chronically sick children in Finland, by disease categories
Diagnosis
Number of observations
Relalive share (~)
Prevalence in Finland (per 1000)
l. Allergic diseases 2088 25 2. Tuberculosis 60 1 3. Endocr/nokrgica| diseases 458 5 4o Congenita'l diseases and malformalions 2877 35 5, Sequelae of injuries ,220 3 6. Diseases of Ihe nervous system 598 7 7, Psyc~/iatric ,diseases 5:14 6 8. Diseases o f ~he :urinary syslem 345 4 9. Blood diseases 202 2 10. Other chronic diseases 959 12 -(1 I. Diseases 'of the sense organs .excluded from the -presentation .of the results) Total 8321 100
To~al number of chronically sick children
8-7 0-3 1-9 12-0 0.9 2-5 2.1 1-4 0-8 4-0
9700 300 2100 13,000 1000 2500 2500 1600 900 4400
34"8
.38,500
Informants Public health nurses reporte d the.data. Public health nurses are registered nurses who have received one year of postgraduate training in preventive medicine and public health. The Finnish communes (the smallest independent local administrative unit) have a statutory obligation to hire public health nurses to carry out activities primarily pertaining to maternity and child health and preventive medicine. The public heaRh nurses cover the entire child population o f a commune and maintain comprehensive and up-to-date records o f all children in their charge.iThey are also familiar with the livin~ conditions o f the children, The informants of the study were selected by means o f a txvo'sta~e probability sample, First 280 communes were selected using sampling with probability proportional to the size o f the communes. The Provincia:l Health Officers provided the names of all public
274
H. Vuori, 1t. Urponen and "1".Peltonen
health nurses working ]n the selected communes. From these ~ames, one out of four was randomly picked. This stage yielded 400 public health nurses. Out of these, 374 (94,%) consented to participating.
Study population The public health nurses were asked to report, using a mailed questionnaire, the names, ages, sex, parents and diagnosis of chronically sick children under 16 years o f age in their district they were aware of and whose illness corresponded with the criteria stated above. In the questionnaire, all the diagnoses included in the study were listed and the public heatth nurses ticked the appropriate diagnosis 'for each reported child. To enable the computation of the prevalence rates, the :informants also reported the total number of children under 16 years of age in their district. The latest (1970) census data of the communes were used to obtain the age distribution of these children.
Lhnimtions o f the stud), The material represents only the non-institutionalized child population with a manifest chronical illness known to the public health nurses. The definition of chronic illness used in this study emphasizes the social aspects of chronic diseases (long duration, consequences) at the expense o f a medically clearly defined diagnosis. This emphasis was appropriate in the light of the objectives of the subsequent phases of the study but constitutes a limitation in a prevalence study.
Size of the sample Altogether 8321 chronically sick children were reported, 51 ~ of them being boys and 49 ~ girls. Results To provide an overall view of the magnitude of the problem, as seen from the social point of view, the total prevalence and the distribution of the broad disease categories is being presented. D~ta on diseases of the sense organs that were originally collected are excluded from all results, as this group contained a large number o f poorly defined refraction errors.
The ,total preralence The total prevalence o f chronic diseases was 34-9 per 1000 children under 16 years of age. The morbidity was highest on one hand in Ahvenanmaa (the archipelago in .the Baltic Sea between Sweden and Finland) and on the other hand in the predominantly rural, scarcely 'populated and relatively under developed northern and eastern provinces with exception of the province of Pohjois-Karjala. The estimated number of chronically sick children, .as defined in this study, was 38,500. Some of fhe children had several chronic diseases: 7-5% had itwo and 1 ~/o,three or more diseases.
Prevalence by disease categories Table I gives the number of observed cases, the relative share (~(;), the prevalence and an estimate of the total number of cases in Finland, by disease categories. The emerging picture is clear: Congenital diseases and malformations ( 3 5 % ) a n d allergic diseases (25%) were by far the two largest groups. All the other groups accounted t'or less than 10~ each. The
Chronic disease in children
275
relative importance of various diseases and their combined total prevalence in different age groups is s~hown in Figure 1. The total prevalence more than doubles when moving from the first five-year group and then remains stab Je. The most conspicuous finding with regard to the disease groups was the rapid decrease of the share of congenital diseases and malformations during the first years of life. The prevalence of endocrinological diseases, psychiatric conditions and sequalae of injuries slightly increased and that of blood diseases decreased with advancing age. The share of the other groups was rather constant.
0-4 Per years cent of age ~00%
5 -9 yeors of age
IO-15 years of -age Other chronic diseases
90% Endocrinotogical d iseases 80%
SequalC~e of injuries Psychia~Itic diseases
7'0%
Diseases of nervGus syslems
60%
Oiseoses of the urinar~ .Syslem 50%
40%
At~ergic diseases
30°./0
Blood diseases
20% Conqen.i~ol diseases and malformations
10%
~
~
Total .prevalence per I OO0
Figure I. The relative share (%) of various diseases in different age groups.
Discussion The reliability of the results :of this study can be scrutinized in the light of the melfhods used and their va]idity by comparing them with other known data concerning the morbidity of the Children in Finland.
276
H. ]'5tort, H. UJponen and 7". Peltonen
Reliability of the resu#s The primary source of data was the records of the public health nurses. 'This is on .one hand a limitation: only morbidity known to the nurses was covered. No efforts were made to screen for latent diseases. It can, on the other hand, be argued that as the public health nurse network covers the entire child population and as chronic diseases almost by definition are known to the parents, this source probably provides the best available and indeed quite comprehensive estimate of the magnitude of the problem. It is almost certain that the records of the various healih care institution, s (lecal health centres., hospitals etc.) would have yielded a much lower figure. Finally, Ihe Finnish public health nurses are reno~vned for the high quality of their training a n d work. The sampling procedure used in the study should provide a ,representative geographical coverage. The list o f the public health nurses working in the selected communes was a complete one. The response rate (94.0/o) was high. There may be some bias in the age distribution of the children. In many communes, one public health nurse was responsible -for just .one age group. In other communes the division of ~asks was based not on age but on geographical or administrative areas. The informants did, however, provide .data for all age groups, This means that .in the former group of communes, they had to get part of the .information from the records of other public health nurses. It may be that the data originating from their own records are more reliable than the data emanating .from those o f others.. As there is no reason to believe that the sample was biased in favour of any particular age group, it can, however, be assumed that the possible errors balance each other. The greatest potential source of error is the questionnaire. The information concerning the age and sex o f the children is probably highly reliable, whereas the diagnostic data may be less reliable. This applies especial.|y to some individual diagnosis, not so much to the larger classes o f diagnosis. Some diseases are .clear: e.g. diabetes, congenital heart disease and cleft palate. We believe 'that with regard to such diseases, the material is comprehensive and the diagnosis reIiable. Other diseases are much more vague, e.g. allergic dermatitis, psychiatric conditions and sequalae o f injuries. These conditions may have been systematically under- or over~ reported and there may be errors o f diagnosis. The public health nurses have obviously defined such diseases differently. This was evidenced by comparisons between various communes ,and between nurses working in the same commune. For this reason, no comparisons have been .attempted between towns and rural areas let alone between smaller :geographical units. It can be assumed that the differences of definitions have resulted in under-reporting of minor conditions. As a consequence, the results probably represent a minimum estimate. It should, however, b e emphasized that, in the great majority o f cases, the diagnoses were originally m a d e or later confirmed :by a local physician or some hospital. This ,is especially true o f the more serious diseases. As a consequence, the possible errors of diagnoses primarily concern minor conditions.
Validio, of the resu#s In Finland the data on the prevalence o f chronic diseases of .children are rather scanty. The National Sickness Insurance furnishes certain chronically sick patient groups with free drugs. ~-~n Table 2, the number o f children entitled to free drugs is compared with the estimated number provided b y this study, in certain diseases. The ,data are very concordant. Gylling & Soivio ~ have estimated that in Finland, among :children 0-45 years of age, there are approximately ,I00 cases of cleft palate in each one year cohort which yields a
Chronic disease hr children
277
total of 1500. The estimate of this study is only 900, This difference probably results from the fact that in the older age groups, the condition has been repaired~ The informants have not reported these cases, which is completely in accordance with the objectives of the study and thus partially corroborates the validity o f the results. TABLE2. The number of children entitled to free drugs by lhe Naliorxa] Sickness Insurance and the estimated .number of chronicalb ~ s~ck children based .on the results of this sludy, in certain diseases
Disease Diabeles 'Chronic pyelonephrifis Rheumatoid arthritis Leukemia
Number of children ent~tted Io free drugs (under t5 years of age)
Esti~naled.nut.abet of chrordca'.lly sick children~under 16 3'ears of age)
1569 963 302 77
~600 1200 300 I00
Significance of the results There are two earlier estimates o f the prevalence o f children ,, chroni,~ diseases in ~inland. The Task Force on the Organization ,of Long-term Care s gave 16,000 as the number of chronically sick children. This figure, however, only represents "the t:ip of the iceberg"., the most chronic cases entitled t o various social security benefits. The estimate w a s based on available s,'atistics and studies. The fact that it .included institutionalized children enhances the difference to the present study. V'2itin~nen ~ defined a child's chronical disease ~n the same way as in this study. He also used public health nurses as informants. H e included institutionalized children in his material. When this group is excluded from our .material, our estinaate (38,000) is clearly higher than that of V/i~in~inen (30.900). This study was based on the assumption that Chronic diseases o f chitdren are more common than generally expected and revealed by the official statistics and that the treatment -of these diseases may be partly neglected. The results .of this study corroborate the first part o f the assumption. The latter part o f the assumption is the object of the subsequent phases o f the study. Already o n the basis o f this study, it can be concluded that the prevalence reaches its highest values in areas where medical services are in shortest supply. The product moment (r) and rank order (Kendall's w) correlations between the pediatrician ratio (.per 1000 inhabitants) and the prevalence figures and between the pediatric bed ratio (per I000 inhabitants) and the prevalence :figures by pro'vinces are as follows: /"
W
Pediatrician ratio 0.34 0-28 Pediatric bed ratio .0,48 0-38 This is in accordance with the ubiquitous finding of most studies related to the geographical distribution of adult mobidity: the higher the morbidity, the more meagre the supply o f health services. Acknowledgements The study was supported by grants from the Medical Board of the Finnish Academy, lhe Finnish Cultural Foundation and the Alfred Kordelin Foundation. The investigators also gratefully acknowledge ~the help of the participating public health nurses.
278
I. 2. 3. 4.
H. Vuori, It. Urpo.~ten and 7: Peltonen
References Gylting, U. & Soivio, A. I. (1962L Frequency, morphology and operative mortality in cleft lip and Dalate in FinlaHd. Acta chit. stand. 123, 1-12. Kansanel8kelaitoksen tilastollinen vuosikirja (Yearbook of the National Pensions Inslitule) (1970). Helsinki: The Institute. PitkaaikaishoJtotoimikunnan mietint6 (Report of the Task Force on the Organization of Long-term Care) ('~970). Helsinki: Komiteanmietint6 1970: B 76. V~i~inanen, I. (1972). Pitkfiaikaissairaiden lasten hoidon mrve maassamme 4The need of care of chronically sick children). Sos. l ~ k e t . Aikak L 10, 7.