An Epidemiological Approach to the Study Of Users and Nonusers of Child Health Services BEATRICE J. SELWYN, RN, DSCHYG
Abstract: A case-comparison study was carried out in 1972 to determine the characteristics of users and nonusers of child health services. A sample of 529 mothers with children under five years of age (eligible children) residing in one poor barrio in Cali, Colombia was selected. The characteristics of mothers and their eligible children were described in relation to their use or nonuse of health services and a set of indicators was developed which differentiated the nonuser group from the user group. A two-stage sampling technique was used. First, blocks in the barrio were sampled, and second, an equal number of mothers with eligible children who
used and who did not use services in the year prior to the study were selected for interview. Nonusers were matched with users on distance from home to local health center. The set of indicators which best discriminated the groups was: the number of eligible children, age of mother, access to free medical care, the action proneness score (attitudes), and knowledge of health, illness, and services. The study method permitted identification of the target populatibon for services, determination of current patterns of use, and quantification of morbidity and immunization levels. (Am. J. Public Health 68:231-235, 1978)
Introduction
The Relevant Literature
The basic purpose of this research was to obtain information about utilization and morbidity patterns in a barrio (neighborhood) population prior to the institution of a new health care delivery program* for children less than five years of age in Cali, Colombia. The information obtained was useful in planning and later in evaluating, the services offered. The objectives for this report are to describe the mothers with children less than five years of age who used child health services in Cali, Colombia, as well as those who did not use services, and to demonstrate the set of indicators which best differentiated the nonuser group from the user group.
Literature related to utilization research indicates general agreement on the factors involved in differential utilization, but studies often report different types of relationships between the factor and utilization behavior. ' Study methods vary and ascertainment of study populations differ. This influences the observed relationships. Utilization research has seldom been conducted using similar study design and methods in different populations.' A version of Andersen's2 original model is used as the basis for presenting the variables included in this study. Backgroundfactors, such as age,2 family size, 2-4 length of residence,5 education,4 6 illness,2' previous use,4 and cul-
Use was defined as taking an eligible child (one less than five years of age) to a formal health service (private physician, hospital, health center) during the year prior to the study. Nonuse was the converse; however, the child may have been taken to a pharmacist, curandero, or other traditional service. *Research Program in Health Delivery Prototype Services (PRIMOPS) of the Universidad del Valle School of Medicine, Department of Social Medicine, Cali, Colombia.
Address reprint requests to Dr. B. J. Selwyn, Assistant Professor of Epidemiology, University of Texas School of Public Health, Health Science Center at Houston, P.O. Box 20186, Astrodome Station, Houston, TX 77025. This paper, submitted to the Journal January 29, 1976, was revised and accepted for publication May 3, 1977. AJPH March, 1978, Vol. 68, No. 3
,
ture, 1. 7describe the mother-child unit in its micro-environment and in society. The enabling factors, such as income, 6, 8 socioeconomic level,2 6 distance to health services,4 6 8 and possession of health insurance,2' 8, allow the mother-child unit to use services if so inclined. Health service characteristics influence and limit patterns of use;4 8, 9 therefore, types and numbers of health services available are described. Predisposing factors, such as knowledge and attitude toward services, health, and illness,6 10-12 influence the inclination to use or not to use health services.
Study Methods Study Area The study was carried out on a sample of mothers with at least one child under five years of age who resided in bar231
SELWYN
rio Union de Vivienda Popular in Cali, Colombia. Cali, located in the western part of Colombia close to the equatorial line, is Colombia's third largest city with a population of 917,000 residents. The barrio contains more than 57,000 inhabitants in one square mile of area. It is an urban ghetto with poor housing, few municipal services, and much poverty. Two medical services were available in the barrio: a municipal health center and a church-supported health center. Both provided pediatric services for illness needs and well-child control. The prevailing system of payment was fee-for-service and service was obtained on a first-come/first-serve basis. Study Design and Method A retrospective case-comparison study design was employed in the population and users and nonusers were matched on distance to local health services. No other direct matching was done but, by selection of the study area and population, several other factors (socioeconomic level, the general environment, and the cultural background of the population) were partially controlled. A two-stage sampling technique was used in which the first stage was a sample of the blocks in the barrio and the second stage was a sample of the study population. Previous studies13' 14 carried out in similar areas of Cali were used to determine the sample size and sampling ratio. The aim was to obtain equal numbers of users and nonusers for the study. The disparately large proportion of users estimated in the population (72 per cent) necessitated different sampling ratios for each group. For users it was 10 per cent; for nonusers it was 25 per cent (see Figure 1). Listing was done on study blocks to identify the mothers with eligible children and their claimed use/nonuse for the past year. Mothers were classified as users or as nonusers, and each group was sampled according to the predetermined ratio.15 Listing and interviewing on each study block was accomplished on the same day. During September and October 1972, information was collected in a personal interview from mothers (or mother surrogates) by Colombian women trained to use a carefully constructed interview schedule. The schedule was translated from English to Spanish, then translated back into English
by another
person. The final number of completed inter529 mothers: 234 nonusers and 295 users. The completion rate of attempted interviews was 97 per cent. Environmental information about the dwelling unit, and sociodemographic characteristics of the family and the mother were obtained from the mother. The mother's "proneness to act" with regard to her child's health needs or illness was ascertained by a set of attitude items which were scored using a five-point Likert technique. Knowledge of childhood illness, child health practices, and health service personnel was obtained by using items weighted so that a higher score indicated more "formal" medical knowledge. A mother's level of traditionalism or modernism was determined through application of the Short Form 5 of the Overall Modernity (OM) Scale.16 The mother reported in detail illness and immunization use for each eligible child for a one-month period. A calendar helped her confine recall of events to the desired time period. Although she reported health service use for the remaining 11 months of the year, she was not asked for details since her ability to remember these facts would have decreased over time. Utilization data were validated by comparing information for the year from a sample of users and nonusers with health services records of health centers and public hospitals in Cali. There was little discrepancy between claimed use on interview and actual use as recorded in the health service record. Chi-square analysis was used to reduce the large number of variables to those which showed a significant relationship (P < 0.05) with the selection criterion. Those variables significantly related to use and nonuse were subjected to discriminant function analysis. A correlation coefficient was calculated between each variable and the discriminant function score to provide information on the proportion of the function explained by the variable. The correlations were tested for significance with univariate F-tests. Wilk's Lambda17 was used to test if the discrimination of groups was a chance occurrence.
views
was
Results The listing demonstrated that 65 per cent of families had a child under five years of age (eligible child). Use of services
FIGURE 1: Sampling Ratio to Obtain Equal Numbers of Users and Nonusers on Each Study Block 232
in the past year was claimed by 67 per cent of the mothers listed. These results were similar to estimates from other studies13' 14 which were used to calculate sampling ratios. No differences in general social and economic characteristics were found between user and nonuser mothers (Table 1). The pattern of racial mixture was representative of the barrio as a whole. The formal education level was limited; common law unions were usual. The population was moderately transient and the median income was $1,000 pesos or less per month ($20 pesos per U.S. dollar). The unemployment rate was not impressively high (8 per cent). Those who were employed, however, worked mostly in unskilled commercial jobs. Statistical differences in background factors were found for mother's age and the number of eligible children in the AJPH March, 1978, Vol. 68, No. 3
USE/NONUSE OF CHILD HEALTH SERVICES TABLE 1-Selected Characteristics of Nonusers and Users in the Area User
Nonuser % (N = 234)
% (N = 295)
22.2 21.4 26.9 29.5 100.0
22.0 20.0 26.4 31.6 100.0
1-3 years 56.4 29.9 Morethan3years No school 13.7 TOTAL 100.0 Civil Status Married 53.0 Common law 32.9 Other 14.1 TOTAL 100.0 Time in the Area 0-12 months 30.3 13-36 months 27.8 37-120 months 41.9 TOTAL 100.0 Income per Month (Amount in pesos: $20 pesos per U.S. dollar) $0-500.00 35.5 44.0 $501-1,000.00 $1,001 and more 15.4 Don't know 5.1 TOTAL 100.0
53.2 34.2 12.6 100.0
x2 =1.126
61.0 29.2 9.8 100.0
x2 = 4.091
33.9 27.1 39.0 100.0
x2= 0.803
Descriptive Factor
Result Chisquare
Race
White Negro White-Indian Negro Mix TOTAL Education
26.1 48.1 18.0 7.8 100.0
x2= 0.309 p = n.s.
p = n.s.
p = n.s.
p = n.s.
x2
=
6.18572
p = n.s.
n.s. = not significant
family. The user group was younger on the average (30 years of age) than the nonuser group (32 years of age). In Table 2 it may be seen that 76 per cent of users versus 60 per cent of nonusers were 34 years of age or younger, and the number of eligible children per mother was higher for the user group. Most user mothers (58 per cent) had two or more eligible children, while nonuser mothers (68 per cent) usually had only one eligible child. User mothers had more eligible chilTABLE 2-Mother's Age and Number of Eligible Children by Nonuser and User User
Nonuser %
Factor
(N
=
234)
Result
%
(N
=
295)
Chi square
TOTAL
TABLE 3-Number of Eligible Children and Size of Study Family by Age of Mother for Nonuser and User Age less than 35 years Nonuser User (%) (%) (N = 140) (N = 223)
Number of children
1 2 3-4
57.1 34.3 8.6
x= 18.032, p
Age of Mother in Years 10-24 25-34 35-44 45-80 TOTAL Number of Children 1 child 2 children 3-4 children
dren than nonuser mothers even when adjustment was made for age, but no significant difference was noted between users and nonusers with respect to total family size when adjustment was made for mother's age (Table 3). Most of the enabling factors were either controlled for, e.g., distance to health services, or showed inconsequential differences between the groups, e.g., employment and income. Occupational type differed little between user and nonuser heads-of-household, but the place of employment differed. Some employers offered a program of free maternal-infant medical care through the Colombian Social Security Service and other agencies; other employers did not offer these benefits. More user mothers claimed that the family had rights to free medical care than did nonuser mothers (see Table 4). Two of the measurement instruments for the predisposing factors, the attitude score (Action Proneness, or AP, Score), and the knowledge score (Health, Illness, and Service, or HIS, Score), demonstrated that nonusers were significantly different from users (Table 5). Nonusers were less prone to act, and less knowledgeable than users. The traditionalism-modernism scale revealed no difference between the groups. Each item of each score was related to use and nonuse. Among items of the AP Score, fear of immunization and disregard for the necessity to have check-ups for non-ill infants were strongly associated with nonuse. Four of the HIS Score items were strongly associated with nonuse. Nonusers lacked knowledge about: I) reasons for immunizations, 2) treatment for childhood diarrhea, and 3) how to stop a contagious illness. They believed that: 4) a pharmacist's main function is to treat illness. Two items from the OM Scale were highly relevant to the differentiation of nonuser and user. Nonusers were negative about limiting family size and they rarely read newspapers.
Age 35 years or more Nonuser User (%) (%) (N = 94) (N = 72)
37.2 40.4 22.4 = 0.0001
82.9 17.1 0
x2
55.6 36.1 8.3
= 16.401, p = 0.0001
Number of persons in family
24.8 35.0 32.1 8.1 100.0
34.2 41.4 18.0 6.4 100.0
67.5 27.4 5.1 100.0
41.7 39.3
X2 =41.368
19.0 100.0
p = 0.0001
x2
=
16.438
p = 0.001
2-4 5-6 7-14
37.1 35.7 27.2
x2
=
TOTALS (%)
41.3 36.3 22.4
1.2344, p = n.s.* 100.0 100.0
19.2 28.7 52.1
x2
23.6 19.5 56.9
= 2.23219, p = n.s.* 100.0 100.0
*n.s. = not significant
AJPH March, 1978, Vol. 68, No. 3
233
SELWYN TABLE 4-Rights to Free Medical Care by Nonuser and User
Family has rights?
Yes No TOTAL
Nonuser
User
% (N = 234)
(N = 295)
17.9 82.1 100.0
3606 63.4 100.0
%
Chi-square Result
X2
=
21-460
21.4000 p=000 =
TABLE 5-Action Proneness Score and Knowledge Score by Nonuser and User
Score
Action Proneness lowest low medium high TOTAL Health, Immunization and Service
Nonuser
User
% (N = 234)
(N = 295)
27.8 22.2 26.9 23.1 100.0
13.6 20.3 26.4 39.7 100.0
26.9 23.1 24.8 25.2 100.0
20.3 16.3 26.1 37.3 100.0
Chi-square Result
%
x2 = 24.623 p = 0.0001
Knowledge lowest low medium high TOTAL
X2 =11.611 p = 0.01
TABLE 5-Results of the Discriminant Function Analysis Correlation Variable
Coefficient*
Value of F Ratio**
P Value of F Ratio
1. Number of eligible children per family 2. Action Proneness Score 3. Age of mother 4. Knowledge score 5. Rights to free service
-0.6288 -0.4652 +0.4407 -0.4143 -0.3815
36.99 19.49 17.40 15.31 12.91
0.0001 0.0001 0.0001 0.0001 0.0001
*Minus sign indicates a negative association with nonuse. Plus sign indicates a positive association with nonuse. **F-ratio degrees of freedom were: between-groups = 1; withingroups = 431. F-ratio indicates the outcome of the univariate F-tests done on the correlations.
Several sets of variables, all characteristics directly related to the mother, were subjected to discriminant function analysis with the objective of identifying those variables which best separate the mothers into the nonuser group or the user group. Table 6 contains the results of the analysis. The five best discriminating variables were grouped to comprise a "set of indicators of nonuse". The value of the Wilk's Lambda test of discrimination was 6.098 for 17 and 415 degrees of freedom, yielding a probability of less than 0.0001 that the separation of groups occurred by chance. The morbidity experience of the child was assumed to be a factor in the need of illness action, as were immuniza234
tions for health action. For a four-week period, the rate of morbidity among children of nonuser mothers was 43.8 per cent, as compared to 53.1 per cent for children of user mothers. However, user mothers consulted a physician for ill children during the month in only 30 per cent of the cases. Nine per cent of children of users went to a health service for wellbaby checks and immunizations in the month. Immunization rates were lower among children of nonuser mothers. Fortytwo per cent of children of nonusers had received at least one immunization compared to 64 per cent of children of users.
Discussion Indicators of User and Nonuser Status The set of five indicators produced by discriminant function analysis indicated the nonuser group was older, had fewer eligible children, demonstrated lower knowledge and attitude scores, and was less likely to have rights to free medical care than the user group. Of interest is the fact that nonusers, whether young or old, tended to have fewer eligible children than users (Table 3). Nonuse seems to be a function of the number of children in the eligible age group, since there was no relationship found between total family size and use status. This contrasts with study results of Picken and Ireland.3 Nonusers reported fewer cases of illness in a month than users. These findings support the idea that the incidence of illness is associated with the number of young children3 (fewer children means less illness), and that the occurrence of illness is related to utilization. It is likely that users perceived illness severity differently from nonusers, since user mothers were younger, and had more and younger children. This picture of user mothers is similar to the users of a neighborhood health center in the United States reported by Reynolds.18 The nonuser group tended to have lower action proneness scores and lower knowledge scores about health activities than the user group. It is possible that the users' attitude and knowledge levels increased due to contact with the health system. Ideally, attitudes should be measured prior to entry into the system and all mothers revisited at a later date to determine if use had occurred. This was unrealistic, however, for the present study. Users were also more likely to have access to free care. As Berkanovic8 points out, when illness is perceived and ability to pay exists, use of services occurs despite the existence of other barriers such as distance to service. Indeed, the free clinic of the Colombian Social Security Service (ICSS) was the second most frequently used health service, even though an hour-long bus ride was required to reach it. ICSS provided health care for infants under one year of age and more users than nonusers had children in that age group. Ethnicity and educational level differed greatly between providers of health services and the women in the study, and these disparities are reported to affect utilization of health services.7 Other authors have shown that users have higher educational levels,4 6 but such results are not supported by AJPH March, 1978, Vol. 68, No.3
USE/NONUSE OF CHILD HEALTH SERVICES
findings of this study. Users and nonusers had similar educational experiences, even when adjustment was made for mother's age. Personal characteristics of a mother, in combination with greater perceived need and/or better access to services, seemed to foster use. Study Methodology The epidemiological approach offered in this paper permits investigation of the characteristics of the total target population for health services, users and nonusers. The method yields patterns of physician, pharmacist, and traditional service use; quantification of the size of various user and nonuser groups, and differential morbidity rates. Various rates of use in health and in illness (frequency and volume rates, for example) can be calcualted for a time period, and multiple use of services for one illness episode can be described. Carrying out such investigations prior to and after institution of health services in an area provides information for planning services to meet the needs of the target group and for evaluating the impact of services on the group's utilization patterns and health over a time period. Answers obtained in the interview suggest ways to structure delivery systems to the subculture of the population to be served, e.g., taking immunization services and information regarding the local center to the homes of the mothers rather than waiting for them to come to the service. Nonusers do not read newspapers, but they do have radios. Factors such as deficient health knowledge and lack of rights to free care point to areas where the educational and economic systems might interact with the health system in seeking suitable solutions. The frequency of a characteristic in the total population is useful information for planning. Study data can be used to estimate values for the target population by simple recalculation of marginal frequencies found in the sample. The sampling procedure required that one-tenth of all users and onefourth of all nonusers be selected. By multiplying the number of users with a given characteristic by ten and the number of nonusers by four, the total number of mothers with the characteristic can be estimated. Using the methods of this study, baseline information can be collected on the characteristics of the target population prior to and after changes are made in the delivery system. This information permits planning of a relevant system and evaluating the impact of the system on the status and activities of the target population. In this manner, research can be carried out on the agent of change (the type of delivery system) in relation to the characteristics of the population served.
AJPH March, 1978, Vol. 68, No. 3
REFERENCES 1. McKinlay, J. B. Some approaches and problems in the study of the use of services-An overview. J. Health Soc. Behav. 13:115-152, 1972. 2. Andersen, R. A behavioral model of families' use of health services. University of Chicago Graduate School of Business, Center for Health Administration Studies, Research Series 25, 1968. 3. Picken, B., and Ireland, G. Family patterns of medical care utilization. J. Chronic Dis. 22:181-191, 1969. 4. Collver, A., TenHave, R., and Spear, M. C. Factors influencing the use of maternal health services. Soc. Sci. Med. 1:293-308, 1967. 5. McKinlay, J., and McKinlay, S. M. Some characteristics of utilizers and underutilizers of health and social welfare services. J. Health Soc. Behav. 13:369-382, 1972. 6. Kegeles, S. S. Some motives for seeking preventive dental care. J. Am. Dent. Assoc. 67:90-98, 1963. 7. Press, I. Urban illness: Physicians, curers and dual use in Bogota. J. Health Soc. Beh. 10:209-218, 1969. 8. Berkanovic, E., and Reeder, L. G. Can money buy the appropriate use of services? Some notes on the meaning of utilization data. J. Health Soc. Behav. 15:93-99, 1974. 9. Andersen, R., and Newman, J. F. Societal and individual determinants of medical care utilization in the United States. Milbank Mem. Fund Q. 51:95-124, 1973. 10. Alpert, J. J., Kosa, J., Haggerty, R. J., Robertson, L. S., and Heagarty, M. Attitudes and satisfactions of low income families receiving comprehensive pediatric care. Am. J. Public Health 60:499-506,1970. 11. Smith, Jr., L., and Kane, R. Health knowledge and symptom perception: A study of a rural Kentucky county. Soc. Sci. Med. 4:557-567, 1970. 12. Rosenstock, I. M. Why people use health services. Milbank Mem. Fund Q. 44:94-127, 1966. 13. Villadiego, F. Estudio de Hechos Vitales 1969-1970. ("Vital Statistics Study 1969-1970.") Department of Social Medicine, University del Valle, Cali, Colombia, 1970. 14. Martinez S., J. H., Martin Pineda Vasquez, R. Rodriquez P., and Ivan Cardona A. Impacto de la Educaci6n Sanitaria en el Estado Nutricional Infantil en el Area Urbana. ("The Impact of Health Education on the Nutritional Status on Infants in an Urban Area.") Mimeograph, Department of Preventive Medicine, I.C.S.S. Cali, Colombia, 1970. 15. Selwyn, B. J. Use and Nonuse of Child Health Services in Cali, Colombia. Doctoral dissertation, Tulane University School of Public Health and Tropical Medicine. Michigan: Xerox, University Microfilms, No. 74-24, 166, 1974. 16. Horton-Smith, D., and Inkeles, A. The OM scale: A comparative socio-psychological measure of individual modernity. Sociometry 19:353-377, 1966. 17. Cooley, W. W., and Lohnes, P. R. Multivariate data analysis. New York: John Wiley and Sons, Inc., pp. 243-261, 1971. 18. Reynolds, R. A. Improving access to health care among the poor-the neighborhood health center experience. Milbank Mem. Fund Q. 54 (Winter):47-82, 1976.
ACKNOWLEDGMENTS
This research was supported by the Tulane University International Center for Medical Research, Grant AI- 10050 from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, U.S. Public Health Service, Washington, DC.
235
Abstract: A case-comparison study was carried out in 1972 to determine the characteristics of users and nonusers of child health services. A sample of 529 mothers with children under five years of age (eligible children) residing in one poor barrio in Cali, Colombia was selected. The characteristics of mothers and their eligible children were described in relation to their use or nonuse of health services and a set of indicators was developed which differentiated the nonuser group from the user group. A two-stage sampling technique was used. First, blocks in the barrio were sampled, and second, an equal number of mothers with eligible children who
used and who did not use services in the year prior to the study were selected for interview. Nonusers were matched with users on distance from home to local health center. The set of indicators which best discriminated the groups was: the number of eligible children, age of mother, access to free medical care, the action proneness score (attitudes), and knowledge of health, illness, and services. The study method permitted identification of the target populatibon for services, determination of current patterns of use, and quantification of morbidity and immunization levels. (Am. J. Public Health 68:231-235, 1978)
Introduction
The Relevant Literature
The basic purpose of this research was to obtain information about utilization and morbidity patterns in a barrio (neighborhood) population prior to the institution of a new health care delivery program* for children less than five years of age in Cali, Colombia. The information obtained was useful in planning and later in evaluating, the services offered. The objectives for this report are to describe the mothers with children less than five years of age who used child health services in Cali, Colombia, as well as those who did not use services, and to demonstrate the set of indicators which best differentiated the nonuser group from the user group.
Literature related to utilization research indicates general agreement on the factors involved in differential utilization, but studies often report different types of relationships between the factor and utilization behavior. ' Study methods vary and ascertainment of study populations differ. This influences the observed relationships. Utilization research has seldom been conducted using similar study design and methods in different populations.' A version of Andersen's2 original model is used as the basis for presenting the variables included in this study. Backgroundfactors, such as age,2 family size, 2-4 length of residence,5 education,4 6 illness,2' previous use,4 and cul-
Use was defined as taking an eligible child (one less than five years of age) to a formal health service (private physician, hospital, health center) during the year prior to the study. Nonuse was the converse; however, the child may have been taken to a pharmacist, curandero, or other traditional service. *Research Program in Health Delivery Prototype Services (PRIMOPS) of the Universidad del Valle School of Medicine, Department of Social Medicine, Cali, Colombia.
Address reprint requests to Dr. B. J. Selwyn, Assistant Professor of Epidemiology, University of Texas School of Public Health, Health Science Center at Houston, P.O. Box 20186, Astrodome Station, Houston, TX 77025. This paper, submitted to the Journal January 29, 1976, was revised and accepted for publication May 3, 1977. AJPH March, 1978, Vol. 68, No. 3
,
ture, 1. 7describe the mother-child unit in its micro-environment and in society. The enabling factors, such as income, 6, 8 socioeconomic level,2 6 distance to health services,4 6 8 and possession of health insurance,2' 8, allow the mother-child unit to use services if so inclined. Health service characteristics influence and limit patterns of use;4 8, 9 therefore, types and numbers of health services available are described. Predisposing factors, such as knowledge and attitude toward services, health, and illness,6 10-12 influence the inclination to use or not to use health services.
Study Methods Study Area The study was carried out on a sample of mothers with at least one child under five years of age who resided in bar231
SELWYN
rio Union de Vivienda Popular in Cali, Colombia. Cali, located in the western part of Colombia close to the equatorial line, is Colombia's third largest city with a population of 917,000 residents. The barrio contains more than 57,000 inhabitants in one square mile of area. It is an urban ghetto with poor housing, few municipal services, and much poverty. Two medical services were available in the barrio: a municipal health center and a church-supported health center. Both provided pediatric services for illness needs and well-child control. The prevailing system of payment was fee-for-service and service was obtained on a first-come/first-serve basis. Study Design and Method A retrospective case-comparison study design was employed in the population and users and nonusers were matched on distance to local health services. No other direct matching was done but, by selection of the study area and population, several other factors (socioeconomic level, the general environment, and the cultural background of the population) were partially controlled. A two-stage sampling technique was used in which the first stage was a sample of the blocks in the barrio and the second stage was a sample of the study population. Previous studies13' 14 carried out in similar areas of Cali were used to determine the sample size and sampling ratio. The aim was to obtain equal numbers of users and nonusers for the study. The disparately large proportion of users estimated in the population (72 per cent) necessitated different sampling ratios for each group. For users it was 10 per cent; for nonusers it was 25 per cent (see Figure 1). Listing was done on study blocks to identify the mothers with eligible children and their claimed use/nonuse for the past year. Mothers were classified as users or as nonusers, and each group was sampled according to the predetermined ratio.15 Listing and interviewing on each study block was accomplished on the same day. During September and October 1972, information was collected in a personal interview from mothers (or mother surrogates) by Colombian women trained to use a carefully constructed interview schedule. The schedule was translated from English to Spanish, then translated back into English
by another
person. The final number of completed inter529 mothers: 234 nonusers and 295 users. The completion rate of attempted interviews was 97 per cent. Environmental information about the dwelling unit, and sociodemographic characteristics of the family and the mother were obtained from the mother. The mother's "proneness to act" with regard to her child's health needs or illness was ascertained by a set of attitude items which were scored using a five-point Likert technique. Knowledge of childhood illness, child health practices, and health service personnel was obtained by using items weighted so that a higher score indicated more "formal" medical knowledge. A mother's level of traditionalism or modernism was determined through application of the Short Form 5 of the Overall Modernity (OM) Scale.16 The mother reported in detail illness and immunization use for each eligible child for a one-month period. A calendar helped her confine recall of events to the desired time period. Although she reported health service use for the remaining 11 months of the year, she was not asked for details since her ability to remember these facts would have decreased over time. Utilization data were validated by comparing information for the year from a sample of users and nonusers with health services records of health centers and public hospitals in Cali. There was little discrepancy between claimed use on interview and actual use as recorded in the health service record. Chi-square analysis was used to reduce the large number of variables to those which showed a significant relationship (P < 0.05) with the selection criterion. Those variables significantly related to use and nonuse were subjected to discriminant function analysis. A correlation coefficient was calculated between each variable and the discriminant function score to provide information on the proportion of the function explained by the variable. The correlations were tested for significance with univariate F-tests. Wilk's Lambda17 was used to test if the discrimination of groups was a chance occurrence.
views
was
Results The listing demonstrated that 65 per cent of families had a child under five years of age (eligible child). Use of services
FIGURE 1: Sampling Ratio to Obtain Equal Numbers of Users and Nonusers on Each Study Block 232
in the past year was claimed by 67 per cent of the mothers listed. These results were similar to estimates from other studies13' 14 which were used to calculate sampling ratios. No differences in general social and economic characteristics were found between user and nonuser mothers (Table 1). The pattern of racial mixture was representative of the barrio as a whole. The formal education level was limited; common law unions were usual. The population was moderately transient and the median income was $1,000 pesos or less per month ($20 pesos per U.S. dollar). The unemployment rate was not impressively high (8 per cent). Those who were employed, however, worked mostly in unskilled commercial jobs. Statistical differences in background factors were found for mother's age and the number of eligible children in the AJPH March, 1978, Vol. 68, No. 3
USE/NONUSE OF CHILD HEALTH SERVICES TABLE 1-Selected Characteristics of Nonusers and Users in the Area User
Nonuser % (N = 234)
% (N = 295)
22.2 21.4 26.9 29.5 100.0
22.0 20.0 26.4 31.6 100.0
1-3 years 56.4 29.9 Morethan3years No school 13.7 TOTAL 100.0 Civil Status Married 53.0 Common law 32.9 Other 14.1 TOTAL 100.0 Time in the Area 0-12 months 30.3 13-36 months 27.8 37-120 months 41.9 TOTAL 100.0 Income per Month (Amount in pesos: $20 pesos per U.S. dollar) $0-500.00 35.5 44.0 $501-1,000.00 $1,001 and more 15.4 Don't know 5.1 TOTAL 100.0
53.2 34.2 12.6 100.0
x2 =1.126
61.0 29.2 9.8 100.0
x2 = 4.091
33.9 27.1 39.0 100.0
x2= 0.803
Descriptive Factor
Result Chisquare
Race
White Negro White-Indian Negro Mix TOTAL Education
26.1 48.1 18.0 7.8 100.0
x2= 0.309 p = n.s.
p = n.s.
p = n.s.
p = n.s.
x2
=
6.18572
p = n.s.
n.s. = not significant
family. The user group was younger on the average (30 years of age) than the nonuser group (32 years of age). In Table 2 it may be seen that 76 per cent of users versus 60 per cent of nonusers were 34 years of age or younger, and the number of eligible children per mother was higher for the user group. Most user mothers (58 per cent) had two or more eligible children, while nonuser mothers (68 per cent) usually had only one eligible child. User mothers had more eligible chilTABLE 2-Mother's Age and Number of Eligible Children by Nonuser and User User
Nonuser %
Factor
(N
=
234)
Result
%
(N
=
295)
Chi square
TOTAL
TABLE 3-Number of Eligible Children and Size of Study Family by Age of Mother for Nonuser and User Age less than 35 years Nonuser User (%) (%) (N = 140) (N = 223)
Number of children
1 2 3-4
57.1 34.3 8.6
x= 18.032, p
Age of Mother in Years 10-24 25-34 35-44 45-80 TOTAL Number of Children 1 child 2 children 3-4 children
dren than nonuser mothers even when adjustment was made for age, but no significant difference was noted between users and nonusers with respect to total family size when adjustment was made for mother's age (Table 3). Most of the enabling factors were either controlled for, e.g., distance to health services, or showed inconsequential differences between the groups, e.g., employment and income. Occupational type differed little between user and nonuser heads-of-household, but the place of employment differed. Some employers offered a program of free maternal-infant medical care through the Colombian Social Security Service and other agencies; other employers did not offer these benefits. More user mothers claimed that the family had rights to free medical care than did nonuser mothers (see Table 4). Two of the measurement instruments for the predisposing factors, the attitude score (Action Proneness, or AP, Score), and the knowledge score (Health, Illness, and Service, or HIS, Score), demonstrated that nonusers were significantly different from users (Table 5). Nonusers were less prone to act, and less knowledgeable than users. The traditionalism-modernism scale revealed no difference between the groups. Each item of each score was related to use and nonuse. Among items of the AP Score, fear of immunization and disregard for the necessity to have check-ups for non-ill infants were strongly associated with nonuse. Four of the HIS Score items were strongly associated with nonuse. Nonusers lacked knowledge about: I) reasons for immunizations, 2) treatment for childhood diarrhea, and 3) how to stop a contagious illness. They believed that: 4) a pharmacist's main function is to treat illness. Two items from the OM Scale were highly relevant to the differentiation of nonuser and user. Nonusers were negative about limiting family size and they rarely read newspapers.
Age 35 years or more Nonuser User (%) (%) (N = 94) (N = 72)
37.2 40.4 22.4 = 0.0001
82.9 17.1 0
x2
55.6 36.1 8.3
= 16.401, p = 0.0001
Number of persons in family
24.8 35.0 32.1 8.1 100.0
34.2 41.4 18.0 6.4 100.0
67.5 27.4 5.1 100.0
41.7 39.3
X2 =41.368
19.0 100.0
p = 0.0001
x2
=
16.438
p = 0.001
2-4 5-6 7-14
37.1 35.7 27.2
x2
=
TOTALS (%)
41.3 36.3 22.4
1.2344, p = n.s.* 100.0 100.0
19.2 28.7 52.1
x2
23.6 19.5 56.9
= 2.23219, p = n.s.* 100.0 100.0
*n.s. = not significant
AJPH March, 1978, Vol. 68, No. 3
233
SELWYN TABLE 4-Rights to Free Medical Care by Nonuser and User
Family has rights?
Yes No TOTAL
Nonuser
User
% (N = 234)
(N = 295)
17.9 82.1 100.0
3606 63.4 100.0
%
Chi-square Result
X2
=
21-460
21.4000 p=000 =
TABLE 5-Action Proneness Score and Knowledge Score by Nonuser and User
Score
Action Proneness lowest low medium high TOTAL Health, Immunization and Service
Nonuser
User
% (N = 234)
(N = 295)
27.8 22.2 26.9 23.1 100.0
13.6 20.3 26.4 39.7 100.0
26.9 23.1 24.8 25.2 100.0
20.3 16.3 26.1 37.3 100.0
Chi-square Result
%
x2 = 24.623 p = 0.0001
Knowledge lowest low medium high TOTAL
X2 =11.611 p = 0.01
TABLE 5-Results of the Discriminant Function Analysis Correlation Variable
Coefficient*
Value of F Ratio**
P Value of F Ratio
1. Number of eligible children per family 2. Action Proneness Score 3. Age of mother 4. Knowledge score 5. Rights to free service
-0.6288 -0.4652 +0.4407 -0.4143 -0.3815
36.99 19.49 17.40 15.31 12.91
0.0001 0.0001 0.0001 0.0001 0.0001
*Minus sign indicates a negative association with nonuse. Plus sign indicates a positive association with nonuse. **F-ratio degrees of freedom were: between-groups = 1; withingroups = 431. F-ratio indicates the outcome of the univariate F-tests done on the correlations.
Several sets of variables, all characteristics directly related to the mother, were subjected to discriminant function analysis with the objective of identifying those variables which best separate the mothers into the nonuser group or the user group. Table 6 contains the results of the analysis. The five best discriminating variables were grouped to comprise a "set of indicators of nonuse". The value of the Wilk's Lambda test of discrimination was 6.098 for 17 and 415 degrees of freedom, yielding a probability of less than 0.0001 that the separation of groups occurred by chance. The morbidity experience of the child was assumed to be a factor in the need of illness action, as were immuniza234
tions for health action. For a four-week period, the rate of morbidity among children of nonuser mothers was 43.8 per cent, as compared to 53.1 per cent for children of user mothers. However, user mothers consulted a physician for ill children during the month in only 30 per cent of the cases. Nine per cent of children of users went to a health service for wellbaby checks and immunizations in the month. Immunization rates were lower among children of nonuser mothers. Fortytwo per cent of children of nonusers had received at least one immunization compared to 64 per cent of children of users.
Discussion Indicators of User and Nonuser Status The set of five indicators produced by discriminant function analysis indicated the nonuser group was older, had fewer eligible children, demonstrated lower knowledge and attitude scores, and was less likely to have rights to free medical care than the user group. Of interest is the fact that nonusers, whether young or old, tended to have fewer eligible children than users (Table 3). Nonuse seems to be a function of the number of children in the eligible age group, since there was no relationship found between total family size and use status. This contrasts with study results of Picken and Ireland.3 Nonusers reported fewer cases of illness in a month than users. These findings support the idea that the incidence of illness is associated with the number of young children3 (fewer children means less illness), and that the occurrence of illness is related to utilization. It is likely that users perceived illness severity differently from nonusers, since user mothers were younger, and had more and younger children. This picture of user mothers is similar to the users of a neighborhood health center in the United States reported by Reynolds.18 The nonuser group tended to have lower action proneness scores and lower knowledge scores about health activities than the user group. It is possible that the users' attitude and knowledge levels increased due to contact with the health system. Ideally, attitudes should be measured prior to entry into the system and all mothers revisited at a later date to determine if use had occurred. This was unrealistic, however, for the present study. Users were also more likely to have access to free care. As Berkanovic8 points out, when illness is perceived and ability to pay exists, use of services occurs despite the existence of other barriers such as distance to service. Indeed, the free clinic of the Colombian Social Security Service (ICSS) was the second most frequently used health service, even though an hour-long bus ride was required to reach it. ICSS provided health care for infants under one year of age and more users than nonusers had children in that age group. Ethnicity and educational level differed greatly between providers of health services and the women in the study, and these disparities are reported to affect utilization of health services.7 Other authors have shown that users have higher educational levels,4 6 but such results are not supported by AJPH March, 1978, Vol. 68, No.3
USE/NONUSE OF CHILD HEALTH SERVICES
findings of this study. Users and nonusers had similar educational experiences, even when adjustment was made for mother's age. Personal characteristics of a mother, in combination with greater perceived need and/or better access to services, seemed to foster use. Study Methodology The epidemiological approach offered in this paper permits investigation of the characteristics of the total target population for health services, users and nonusers. The method yields patterns of physician, pharmacist, and traditional service use; quantification of the size of various user and nonuser groups, and differential morbidity rates. Various rates of use in health and in illness (frequency and volume rates, for example) can be calcualted for a time period, and multiple use of services for one illness episode can be described. Carrying out such investigations prior to and after institution of health services in an area provides information for planning services to meet the needs of the target group and for evaluating the impact of services on the group's utilization patterns and health over a time period. Answers obtained in the interview suggest ways to structure delivery systems to the subculture of the population to be served, e.g., taking immunization services and information regarding the local center to the homes of the mothers rather than waiting for them to come to the service. Nonusers do not read newspapers, but they do have radios. Factors such as deficient health knowledge and lack of rights to free care point to areas where the educational and economic systems might interact with the health system in seeking suitable solutions. The frequency of a characteristic in the total population is useful information for planning. Study data can be used to estimate values for the target population by simple recalculation of marginal frequencies found in the sample. The sampling procedure required that one-tenth of all users and onefourth of all nonusers be selected. By multiplying the number of users with a given characteristic by ten and the number of nonusers by four, the total number of mothers with the characteristic can be estimated. Using the methods of this study, baseline information can be collected on the characteristics of the target population prior to and after changes are made in the delivery system. This information permits planning of a relevant system and evaluating the impact of the system on the status and activities of the target population. In this manner, research can be carried out on the agent of change (the type of delivery system) in relation to the characteristics of the population served.
AJPH March, 1978, Vol. 68, No. 3
REFERENCES 1. McKinlay, J. B. Some approaches and problems in the study of the use of services-An overview. J. Health Soc. Behav. 13:115-152, 1972. 2. Andersen, R. A behavioral model of families' use of health services. University of Chicago Graduate School of Business, Center for Health Administration Studies, Research Series 25, 1968. 3. Picken, B., and Ireland, G. Family patterns of medical care utilization. J. Chronic Dis. 22:181-191, 1969. 4. Collver, A., TenHave, R., and Spear, M. C. Factors influencing the use of maternal health services. Soc. Sci. Med. 1:293-308, 1967. 5. McKinlay, J., and McKinlay, S. M. Some characteristics of utilizers and underutilizers of health and social welfare services. J. Health Soc. Behav. 13:369-382, 1972. 6. Kegeles, S. S. Some motives for seeking preventive dental care. J. Am. Dent. Assoc. 67:90-98, 1963. 7. Press, I. Urban illness: Physicians, curers and dual use in Bogota. J. Health Soc. Beh. 10:209-218, 1969. 8. Berkanovic, E., and Reeder, L. G. Can money buy the appropriate use of services? Some notes on the meaning of utilization data. J. Health Soc. Behav. 15:93-99, 1974. 9. Andersen, R., and Newman, J. F. Societal and individual determinants of medical care utilization in the United States. Milbank Mem. Fund Q. 51:95-124, 1973. 10. Alpert, J. J., Kosa, J., Haggerty, R. J., Robertson, L. S., and Heagarty, M. Attitudes and satisfactions of low income families receiving comprehensive pediatric care. Am. J. Public Health 60:499-506,1970. 11. Smith, Jr., L., and Kane, R. Health knowledge and symptom perception: A study of a rural Kentucky county. Soc. Sci. Med. 4:557-567, 1970. 12. Rosenstock, I. M. Why people use health services. Milbank Mem. Fund Q. 44:94-127, 1966. 13. Villadiego, F. Estudio de Hechos Vitales 1969-1970. ("Vital Statistics Study 1969-1970.") Department of Social Medicine, University del Valle, Cali, Colombia, 1970. 14. Martinez S., J. H., Martin Pineda Vasquez, R. Rodriquez P., and Ivan Cardona A. Impacto de la Educaci6n Sanitaria en el Estado Nutricional Infantil en el Area Urbana. ("The Impact of Health Education on the Nutritional Status on Infants in an Urban Area.") Mimeograph, Department of Preventive Medicine, I.C.S.S. Cali, Colombia, 1970. 15. Selwyn, B. J. Use and Nonuse of Child Health Services in Cali, Colombia. Doctoral dissertation, Tulane University School of Public Health and Tropical Medicine. Michigan: Xerox, University Microfilms, No. 74-24, 166, 1974. 16. Horton-Smith, D., and Inkeles, A. The OM scale: A comparative socio-psychological measure of individual modernity. Sociometry 19:353-377, 1966. 17. Cooley, W. W., and Lohnes, P. R. Multivariate data analysis. New York: John Wiley and Sons, Inc., pp. 243-261, 1971. 18. Reynolds, R. A. Improving access to health care among the poor-the neighborhood health center experience. Milbank Mem. Fund Q. 54 (Winter):47-82, 1976.
ACKNOWLEDGMENTS
This research was supported by the Tulane University International Center for Medical Research, Grant AI- 10050 from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, U.S. Public Health Service, Washington, DC.
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