Journal of Community Health Vol. 4, No. 3, Spring 1979-
RURAL ACCESS TO A REGULAR SOURCE OF MEDICAL CARE Virginia C. Kennedy, Ph.D.
ABSTRACT: Household survey data from an adult rural west Texas population were used to investigate the role of demographic, economic, attitudinal, and need-related factors in (a) explaining physician contact and volume of physician visits and (b) differentiating between those individuals who have and those who do not have a regular source of medical care. Fifty-two percent of the variance in visit volume was explained; compared with the findings reported in similar studies, alignment with a regular source of care was more closely associated with visit volume and physician contact. Although the variance explained in having a regular source was only about 18%, the findings suggest that factors determining alignment with a regular source may differ considerably from those determining other dimensions of utilization. Furthermore, patterns evident across several dimensions in rural populations may be quite different from those exhibited in other populations. It is generally a g r e e d that rural r e s i d e n t s - - a l o n g with several o t h e r population s u b g r o u p s - - a r e a m o n g those most disadvantaged by a relative lack o f access to health care services. T h e p r o b l e m is m o r e severe at the point o f gaining entry into the medical care system than it is within the system once entry has been a c h i e v e d ? Previous studies have consistently d e m o n s t r a t e d a relationship between a c k n o w l e d g m e n t o f a regular source and (a) the achievement o f e n t r y into the system (measured by the o c c u r r e n c e o f physician contact within a given period o f time) as well as (b) utilization within the system after entry (measured by the volume o f physician services received d u r i n g a given period o f time). ~-4 T h u s an u n d e r s t a n d i n g o f the factors that d e t e r m i n e w h e t h e r an individual in a rural population is aligned with a regular source o f care may contribute to the design o f a p p r o p r i a t e strategies for r e d u c i n g barriers to access. This p a p e r presents the results o f an e f f o r t to identify the d e t e r m i n a n t s o f alignment with a regular source o f health care in a rural population.
METHODS T h e data for this study are f r o m a household survey c o n d u c t e d in J u n e and July 1976 in three rural census tracts and two contiguous rural communities in and a r o u n d Lubbock County, Texas. This p r e d o m i n a n t l y f a r m i n g and ranching area is located within a radius o f 30 miles f r o m the city o f Lubbock, which has a population o f 185,000 and is the state's leading agribusiness center. At the time Dr. Kennedy is with tile Health SciencesCenters Texas Tech University,Schoolof Medicine, P.O, Box 4569, Lubbock, Texas 79430. 0094-5145/79/1300-0199500.95 O 1979 Human Sciences Press 199
200
j O U R N A L OF COMMUNITY HEALTH
of the survey, residents depended primarily upon doctors in Lubbock for their medical care, since no physician offices were located in the immediate area. A multistage area probability design was employed in selecting the household sample. (Detailed specifications are available from the author.) A modified version of the National Health Interview Survey was administered in a total of 364 households comprising 1,176 individuals. Information was collected concerning household membership and demographics, illness-related disability and hospitalization during the previous year, physician contact experience during the previous year, source of medical care and characteristics of the source, health insurance coverage, and satisfaction with medical care. For purposes of the present analysis a subsample was selected consisting of one adult (defined as age 18 or older) from each of the 364 households. The selection procedure ensured that each adult in the household had an equal chance for inclusion and that the age and sex proportions of the sample reflected the age and sex composition of adult household members within the geographic area.~, 6 The investigation was performed in two stages. The first step was to determine whether the conventional model of physician utilization fits this particular population. The model, described extensively elsewhere, 7"8 characterizes utilization behavior as a function of need for care, measured by perceived and/or evaluated illness, and sets of factors that "predispose" and "enable" the individual to seek care. The importance of the regular source of medical care as an enabling variable was identified in the context of this model; if the model was found not to provide an accurate description of the population under study, the investigation would proceed along different lines. Two dimensions of utilization behavior, physician contact and volume of physician visits, were examined in separate multiple regression analyses. The dependent variable in the first analysis (volume) was the number of ambulatory visits reported by the individual during the previous 12 months. In the second analysis (contact) the dependent variable was a dummy variable coded "1" if the individual had visited a physician at least once within the past 12 months and "0 '~ if the individual had not. From an initial set of over 30 predisposing, enabling, and need-related measures, 12 were selected as independent variables on the basis of the published literature and preliminary correlation analysis. Based on the first stage findings reported below, the second stage of the investigation consisted of identifying the best predictors of alignment with a regular source of medical care. Nine variables yielded sufficiently high zeroorder correlations to be included as independent variables in the subsequent multiple regression analysis; the dependent variable was a dummy variable coded "1" if the individual reported having a regular source of medical care and "0" if no regular source was cited. To ensure that all computations were based on the same population, cases with missing data on any of the variables in the analysis were excluded. This procedure resulted in a reduction of sample size by approximately one
Kennedy
201
f o u r t h , to N = 279. F o r e a c h v a r i a b l e s t u d i e d , p r o p o r t i o n a l d i s t r i b u t i o n s a n d m e a n values i n t h e o r i g i n a l s a m p l e a n d t h e r e d u c e d s a m p l e w e r e c o m p a r e d . D i f f e r e n c e o f m e a n s tests w e r e p e r f o r m e d , a n d n o n e o f t h e v a r i a b l e s e x h i b i t e d a sign'ificant d i f f e r e n c e at t h e 0.05 level. Since t h e p e r c e n t a g e o f total v a r i a n c e e x p l a i n e d b y a n i n d e p e n d e n t variable is a f f e c t e d by t h e o r d e r o f e n t r y i n t o t h e r e g r e s s i o n e q u a t i o n , v a r i a b l e s w e r e e n t e r e d i n t o all e q u a t i o n s i n t h e i r a p p r o x i m a t e causal o r d e C : f a m i l y p r e d i s p o s ing, i n d i v i d u a l p r e d i s p o s i n g , e n a b l i n g , a n d n e e d .
R E S U L T S
Table 1 contains the p e r t i n e n t results of the three multiple regression analyses. P e r c e n t of~R e a n d b e t a values a r e g i v e n f o r t h o s e i n d e p e n d e n t v a r i a b l e s y i e l d i n g a n F ratio s i g n i f i c a n t at o r a b o v e t h e 0.05 level.
TABLE 1 Multiple Regression Results (N = 279) Volume Variable
Pamily size Length of family residence Satisfaction with quality of care Satisfaction with cost of care Satisfaction with convenience of care Race Sex Age Education In labor force Private insurance coverage Medicaid coverage Regular source of care Chronic illness A n n u a l bed days due to illness Hospitalization in past year Total R 2 F
%Re
Beta
2.2
0.001
Contact % Re Beta
Reg. Source %Re Beta
--
--
*
*
*
*
*
*
3.9
0.128
4.2
- 0.115
--
--
*
*
*
*
*
-
-
*
0.220
--*
4.6 . 1.5 * 2.0 * 3.7
0.371 --
* * 2.8
* * 0.169
* * 1.3 -. 0.7 4.4 * . 3.4 3.7
* 0.034 -. . 0.112 -0.057 * .
. 0.080 0.214
11.6
0.353
20.8 52.2 32.7**
0.377
* . 2.9 . --* .
.
. 14.9 -.
.
2.0 19.9 22.7**
*Not included in analysis. **p < 0.01 - - Did not contribute significantly to variance explained.
. 0.099
. 0.146
0.091 * 0.026 * 0.213
. * 18.4 10.2"*
*
202
JOURNAL OF COMMUNITY HEALTH
Nine of the 12 independent variables included in the analysis of physician visit volume accounted for 52.2% of the variance in the dependent variable. As expected, "need" variables (hospitalization, bed days, and chronic illness) were predominant, totaling 36% of the variance. Less expected was the finding that, based on the relative magnitude of beta weights, reported satisfaction with the quality of medical care and the individual's educational level were the next best predictors, followed by acknowledgment of a regular source of medical care. Only three of the 12 independent variables contributed significantly to the 19.9% of variance explained in physician contact; regular source alone accounted for 14.9% of the variance. Past hospitalization and sex made small, although significant, contributions. In the third regression analysis 18.4% of the variance was accounted for, indicating limited ability to predict with this set of variables whether an individual was aligned with a regular source of medical care. Examination of the beta weights reveals that satisfaction with convenience of care and private insurance coverage are the two variables that most effectively distinguish adults with a regular source from those without a regular source of care. Nearly one half of the total variance explained in the equation is accounted for by these two factors. The difference between the two regression coefficients (in unstandardized form) is not significant at the 0.05 level. Next in influence was the presence of a chronic health problem or condition. Length of residence ranked fourth in order of importance, followed by sex and education. The direction of all significant coefficients was positive. The substantive results of the regular source analysis can be summarized as follows. The characteristics that most effectively distinguish those adults with a regular source of medical care include, in order of relative importance, greater satisfaction with convenience of care, private insurance coverage, presence of a chronic health problem, longer duration of residency, female sex, and higher level of education. Presence or absence of a regular source of care was not significantly affected by satisfaction with the cost of care, race, or bed days due to illness.
DISCUSSION
The conventional model predicts volume of physician visits far more successfully in this adult rural population than in rural populations containing nonadults and populations containing either urban or combined rural and urban residents. 1"~'4"1° Using similar concepts and variables, these studies can account for only 15% to 25% of the variance in individual utilization. The model predicts physician contact in this adult rural population approximately as well as in other populations. The role of having a regular source in accounting for both volume and contact, however, is much more substantial than that reported in the studies cited.
Kennedy
203
Andersen and others have suggested that inequities in access to the medical care system could be reduced by providing rural residents with an established entry point in the form o f " a place and/or person to serve as a regular source of medical advice and treatment. 'u Evidence to this effect is abundant and underscores the need to identify the determinants of alignment with a regular source of care. For this reason the proportion of variance explained in the present study is disappointing, and it is difficult to place much confidence in the absolute importance of the independent variables under consideration. Findings concerning the relative importance of specific variable suggest several propositions that merit more conciusive investigation: (1) need factors may be considerably less important in determining alignment with a regular source than they are in determining actual utilization; (2) attitudinal factors, which have consistently been assigned a negligible effect on utilization, may be substantially more important in determining alignment with a regular source; and (3) the lowering of economic barriers to access in recent years, often attributed to the increasing prevalence of health insurance, may not have affected rural populations to the same extent as other populations.
REFERENCES 1. Andersen R: Health service distribution and equity. In R Andersen, J Kravits, OW Anderson (eds): Equity and Health Services: Empirical Analyses in Social Policy. Cambridge, Ballinger, 1975. Pp 9-32. 2. Luft HS, Hershey JC, Morrell J: Factors affecting the use of physician services in a rural community. Am J Public Health 66:865-871, 1976. 3. Bice TW, Rabin DL, Starfield BH, et al: Economic class and use of physician services. Med Care 11:287-296, 1973. 4. Wan TTH, Soifer SJ: Determinants of physician utilization: A causal analysis. J Health Soc Behav 15:100-108, 1974. 5. Kish L: A procedure of objective respondent selection within the household. J Am Stat Assoc 44:380-387, 1949. 6. Backstrom CH, Hursh GD: Survey Research. Evanston, Northwestern University Press, 1963. Pp 50-59. 7. Andersen R, Newman J: Societal and individual determinants of medical care utilization. Milbank Mem Fund Q 51:95-124, 1973. 8. Aday LA, Andersen R: Development of Indices of Access to Medical Care. Ann Arbor, Health Administration Press, 1975. 9. Kerlinger FN, Pedhazur EJ: Multiple Regression in Behavioral Research. New York, Holt, Rinehart and Winston, 1973. 10. Hershey JC, Luft HS, Gianaris JM: Making sense out of utilization data. Med Care 13:838-854, 1975.
RURAL ACCESS TO A REGULAR SOURCE OF MEDICAL CARE Virginia C. Kennedy, Ph.D.
ABSTRACT: Household survey data from an adult rural west Texas population were used to investigate the role of demographic, economic, attitudinal, and need-related factors in (a) explaining physician contact and volume of physician visits and (b) differentiating between those individuals who have and those who do not have a regular source of medical care. Fifty-two percent of the variance in visit volume was explained; compared with the findings reported in similar studies, alignment with a regular source of care was more closely associated with visit volume and physician contact. Although the variance explained in having a regular source was only about 18%, the findings suggest that factors determining alignment with a regular source may differ considerably from those determining other dimensions of utilization. Furthermore, patterns evident across several dimensions in rural populations may be quite different from those exhibited in other populations. It is generally a g r e e d that rural r e s i d e n t s - - a l o n g with several o t h e r population s u b g r o u p s - - a r e a m o n g those most disadvantaged by a relative lack o f access to health care services. T h e p r o b l e m is m o r e severe at the point o f gaining entry into the medical care system than it is within the system once entry has been a c h i e v e d ? Previous studies have consistently d e m o n s t r a t e d a relationship between a c k n o w l e d g m e n t o f a regular source and (a) the achievement o f e n t r y into the system (measured by the o c c u r r e n c e o f physician contact within a given period o f time) as well as (b) utilization within the system after entry (measured by the volume o f physician services received d u r i n g a given period o f time). ~-4 T h u s an u n d e r s t a n d i n g o f the factors that d e t e r m i n e w h e t h e r an individual in a rural population is aligned with a regular source o f care may contribute to the design o f a p p r o p r i a t e strategies for r e d u c i n g barriers to access. This p a p e r presents the results o f an e f f o r t to identify the d e t e r m i n a n t s o f alignment with a regular source o f health care in a rural population.
METHODS T h e data for this study are f r o m a household survey c o n d u c t e d in J u n e and July 1976 in three rural census tracts and two contiguous rural communities in and a r o u n d Lubbock County, Texas. This p r e d o m i n a n t l y f a r m i n g and ranching area is located within a radius o f 30 miles f r o m the city o f Lubbock, which has a population o f 185,000 and is the state's leading agribusiness center. At the time Dr. Kennedy is with tile Health SciencesCenters Texas Tech University,Schoolof Medicine, P.O, Box 4569, Lubbock, Texas 79430. 0094-5145/79/1300-0199500.95 O 1979 Human Sciences Press 199
200
j O U R N A L OF COMMUNITY HEALTH
of the survey, residents depended primarily upon doctors in Lubbock for their medical care, since no physician offices were located in the immediate area. A multistage area probability design was employed in selecting the household sample. (Detailed specifications are available from the author.) A modified version of the National Health Interview Survey was administered in a total of 364 households comprising 1,176 individuals. Information was collected concerning household membership and demographics, illness-related disability and hospitalization during the previous year, physician contact experience during the previous year, source of medical care and characteristics of the source, health insurance coverage, and satisfaction with medical care. For purposes of the present analysis a subsample was selected consisting of one adult (defined as age 18 or older) from each of the 364 households. The selection procedure ensured that each adult in the household had an equal chance for inclusion and that the age and sex proportions of the sample reflected the age and sex composition of adult household members within the geographic area.~, 6 The investigation was performed in two stages. The first step was to determine whether the conventional model of physician utilization fits this particular population. The model, described extensively elsewhere, 7"8 characterizes utilization behavior as a function of need for care, measured by perceived and/or evaluated illness, and sets of factors that "predispose" and "enable" the individual to seek care. The importance of the regular source of medical care as an enabling variable was identified in the context of this model; if the model was found not to provide an accurate description of the population under study, the investigation would proceed along different lines. Two dimensions of utilization behavior, physician contact and volume of physician visits, were examined in separate multiple regression analyses. The dependent variable in the first analysis (volume) was the number of ambulatory visits reported by the individual during the previous 12 months. In the second analysis (contact) the dependent variable was a dummy variable coded "1" if the individual had visited a physician at least once within the past 12 months and "0 '~ if the individual had not. From an initial set of over 30 predisposing, enabling, and need-related measures, 12 were selected as independent variables on the basis of the published literature and preliminary correlation analysis. Based on the first stage findings reported below, the second stage of the investigation consisted of identifying the best predictors of alignment with a regular source of medical care. Nine variables yielded sufficiently high zeroorder correlations to be included as independent variables in the subsequent multiple regression analysis; the dependent variable was a dummy variable coded "1" if the individual reported having a regular source of medical care and "0" if no regular source was cited. To ensure that all computations were based on the same population, cases with missing data on any of the variables in the analysis were excluded. This procedure resulted in a reduction of sample size by approximately one
Kennedy
201
f o u r t h , to N = 279. F o r e a c h v a r i a b l e s t u d i e d , p r o p o r t i o n a l d i s t r i b u t i o n s a n d m e a n values i n t h e o r i g i n a l s a m p l e a n d t h e r e d u c e d s a m p l e w e r e c o m p a r e d . D i f f e r e n c e o f m e a n s tests w e r e p e r f o r m e d , a n d n o n e o f t h e v a r i a b l e s e x h i b i t e d a sign'ificant d i f f e r e n c e at t h e 0.05 level. Since t h e p e r c e n t a g e o f total v a r i a n c e e x p l a i n e d b y a n i n d e p e n d e n t variable is a f f e c t e d by t h e o r d e r o f e n t r y i n t o t h e r e g r e s s i o n e q u a t i o n , v a r i a b l e s w e r e e n t e r e d i n t o all e q u a t i o n s i n t h e i r a p p r o x i m a t e causal o r d e C : f a m i l y p r e d i s p o s ing, i n d i v i d u a l p r e d i s p o s i n g , e n a b l i n g , a n d n e e d .
R E S U L T S
Table 1 contains the p e r t i n e n t results of the three multiple regression analyses. P e r c e n t of~R e a n d b e t a values a r e g i v e n f o r t h o s e i n d e p e n d e n t v a r i a b l e s y i e l d i n g a n F ratio s i g n i f i c a n t at o r a b o v e t h e 0.05 level.
TABLE 1 Multiple Regression Results (N = 279) Volume Variable
Pamily size Length of family residence Satisfaction with quality of care Satisfaction with cost of care Satisfaction with convenience of care Race Sex Age Education In labor force Private insurance coverage Medicaid coverage Regular source of care Chronic illness A n n u a l bed days due to illness Hospitalization in past year Total R 2 F
%Re
Beta
2.2
0.001
Contact % Re Beta
Reg. Source %Re Beta
--
--
*
*
*
*
*
*
3.9
0.128
4.2
- 0.115
--
--
*
*
*
*
*
-
-
*
0.220
--*
4.6 . 1.5 * 2.0 * 3.7
0.371 --
* * 2.8
* * 0.169
* * 1.3 -. 0.7 4.4 * . 3.4 3.7
* 0.034 -. . 0.112 -0.057 * .
. 0.080 0.214
11.6
0.353
20.8 52.2 32.7**
0.377
* . 2.9 . --* .
.
. 14.9 -.
.
2.0 19.9 22.7**
*Not included in analysis. **p < 0.01 - - Did not contribute significantly to variance explained.
. 0.099
. 0.146
0.091 * 0.026 * 0.213
. * 18.4 10.2"*
*
202
JOURNAL OF COMMUNITY HEALTH
Nine of the 12 independent variables included in the analysis of physician visit volume accounted for 52.2% of the variance in the dependent variable. As expected, "need" variables (hospitalization, bed days, and chronic illness) were predominant, totaling 36% of the variance. Less expected was the finding that, based on the relative magnitude of beta weights, reported satisfaction with the quality of medical care and the individual's educational level were the next best predictors, followed by acknowledgment of a regular source of medical care. Only three of the 12 independent variables contributed significantly to the 19.9% of variance explained in physician contact; regular source alone accounted for 14.9% of the variance. Past hospitalization and sex made small, although significant, contributions. In the third regression analysis 18.4% of the variance was accounted for, indicating limited ability to predict with this set of variables whether an individual was aligned with a regular source of medical care. Examination of the beta weights reveals that satisfaction with convenience of care and private insurance coverage are the two variables that most effectively distinguish adults with a regular source from those without a regular source of care. Nearly one half of the total variance explained in the equation is accounted for by these two factors. The difference between the two regression coefficients (in unstandardized form) is not significant at the 0.05 level. Next in influence was the presence of a chronic health problem or condition. Length of residence ranked fourth in order of importance, followed by sex and education. The direction of all significant coefficients was positive. The substantive results of the regular source analysis can be summarized as follows. The characteristics that most effectively distinguish those adults with a regular source of medical care include, in order of relative importance, greater satisfaction with convenience of care, private insurance coverage, presence of a chronic health problem, longer duration of residency, female sex, and higher level of education. Presence or absence of a regular source of care was not significantly affected by satisfaction with the cost of care, race, or bed days due to illness.
DISCUSSION
The conventional model predicts volume of physician visits far more successfully in this adult rural population than in rural populations containing nonadults and populations containing either urban or combined rural and urban residents. 1"~'4"1° Using similar concepts and variables, these studies can account for only 15% to 25% of the variance in individual utilization. The model predicts physician contact in this adult rural population approximately as well as in other populations. The role of having a regular source in accounting for both volume and contact, however, is much more substantial than that reported in the studies cited.
Kennedy
203
Andersen and others have suggested that inequities in access to the medical care system could be reduced by providing rural residents with an established entry point in the form o f " a place and/or person to serve as a regular source of medical advice and treatment. 'u Evidence to this effect is abundant and underscores the need to identify the determinants of alignment with a regular source of care. For this reason the proportion of variance explained in the present study is disappointing, and it is difficult to place much confidence in the absolute importance of the independent variables under consideration. Findings concerning the relative importance of specific variable suggest several propositions that merit more conciusive investigation: (1) need factors may be considerably less important in determining alignment with a regular source than they are in determining actual utilization; (2) attitudinal factors, which have consistently been assigned a negligible effect on utilization, may be substantially more important in determining alignment with a regular source; and (3) the lowering of economic barriers to access in recent years, often attributed to the increasing prevalence of health insurance, may not have affected rural populations to the same extent as other populations.
REFERENCES 1. Andersen R: Health service distribution and equity. In R Andersen, J Kravits, OW Anderson (eds): Equity and Health Services: Empirical Analyses in Social Policy. Cambridge, Ballinger, 1975. Pp 9-32. 2. Luft HS, Hershey JC, Morrell J: Factors affecting the use of physician services in a rural community. Am J Public Health 66:865-871, 1976. 3. Bice TW, Rabin DL, Starfield BH, et al: Economic class and use of physician services. Med Care 11:287-296, 1973. 4. Wan TTH, Soifer SJ: Determinants of physician utilization: A causal analysis. J Health Soc Behav 15:100-108, 1974. 5. Kish L: A procedure of objective respondent selection within the household. J Am Stat Assoc 44:380-387, 1949. 6. Backstrom CH, Hursh GD: Survey Research. Evanston, Northwestern University Press, 1963. Pp 50-59. 7. Andersen R, Newman J: Societal and individual determinants of medical care utilization. Milbank Mem Fund Q 51:95-124, 1973. 8. Aday LA, Andersen R: Development of Indices of Access to Medical Care. Ann Arbor, Health Administration Press, 1975. 9. Kerlinger FN, Pedhazur EJ: Multiple Regression in Behavioral Research. New York, Holt, Rinehart and Winston, 1973. 10. Hershey JC, Luft HS, Gianaris JM: Making sense out of utilization data. Med Care 13:838-854, 1975.
