Use of Ambulatory Health Services by the Near Poor ELIZABETH A. SKINNER, MSW, PEARL S. GERMAN, SCD, SAM SHAPIRO, BS, GARY A. CHASE, PHD, AND ANN G. ZAUBER, PHD
Abstract: Individuals in the gray area between Medicaid eligibility and sufficient income to meet the costs of health care, the near poor, utilize health services less than other groups. As part of a study of health care behavior in an inner-city area based on a household survey of three distinct populations (HMO members, public housing project residents, and a defined geographic area), we examined this question more thoroughly. Survey results show that the near poor had lower levels of use than Medicaid recipients when other factors were controlled. Particularly among those classi-
fied as in poor health, the near poor were more likely to be non-users and less likely to make multiple visits. However, differences in use between the near poor and the Medicaid recipients are substantially and consistently smaller for the HMO users (whose costs were covered by a special contract) than for users of a hospital outpatient department. The patterns persist for regular care received for a chronic condition but not for care sought for episodes of illness. These findings point to the special disadvantage faced by low income individuals who are not receiving Medicaid. (Am. J. Public Health 68:1195-1201, 1978.)
There is growing evidence that the Medicaid program has resulted in a substantial narrowing of the gap in ambulatory health services utilization between the poor and those with considerably higher incomes. Between 1964 (the year prior to passage of legislation authorizing Medicare and Medicaid) and 1971, the ambulatory visit rate increased by almost 60 per cent among the poor to reach 5.8 visits per person per year while it remained stationary at about 5.4 among those in high income families. 1 2 This increased utilization rate seems to be indicative that the poor are receiving more needed services. Much of the increase has been attributed to the Medicaid program's reduction in economic barriers to health services for covered individuals.3-5 It is relevant to the appraisal of the effect of publicly funded programs to find that the segment of the population with low family incomes but not eligible for Medicaid, the "near poor", has failed to show increased service utilization
to the extent found in the poor. Data from the Health Interview Survey revealed that in 1964 physician visit rates were 3.7 for people in families with annual incomes below $2,000, and 4.1 for those in families with incomes between $2,000 and $3,999.1 By 1971, people in families with incomes less than $3,000 made 5.8 visits per person per year, an increase of 2.1 visits, while those with family incomes between $3,000 and $4,999 increased their rate only to 4.9 visits per person per year,2 an increase of 0.8 visits. This report delves more deeply into the use of ambulatory health care services among the near poor and considers the influence of options for such care available within a community. One option is a prepaid group practice (health maintenance program) which receives Public Health Service (Title 314e) funds to cover the cost of services to low income individuals ineligible for Medicaid. Other options include a large teaching hospital outpatient department (OPD). The experience examined relates to near poor adults aged 18-64 years who live in East Baltimore, a low-income, predominantly black community in the City of Baltimore. This age group has been studied because it is the target of relatively few altemative programs to reduce problems of access to care comparable to those available to children through C & Y (Children and Youth) projects and to the elderly through Medicare.
From the Health Services Research and Development Center, Johns Hopkins Medical Institutions. Address reprint requests to Elizabeth A. Skinner, MSW, Research Associate, Health Services Research and Development Center, Johns Hopkins Medical Institutions, 624 N. Broadway, Baltimore, MD 21205. This paper, submitted to the Journal January 18, 1978, was revised and accepted for publication April 28, 1978.
AJPH December 1978, Vol. 68, No. 12
1195
SKINNER, ET AL.
Study Background and Methods As in similar inner-city areas throughout the country, the primary sources of ambulatory care in East Baltimore are hospital outpatient departments and emergency rooms. In this particular community there is one predominant provider, the Johns Hopkins Hospital (JHH). When this study was undertaken in 1974, its OPD was providing services through a traditional arrangement of general medical and specialty clinics staffed by interns, residents, fellows, and attending physicians. Generally, all services provided through the OPD are on a fee-for-service basis. It is possible for individuals to receive services free of charge, but this involves a lengthy application and review process. The East Baltimore Medical Plan (EBMP), which began offering services in November 1971, was developed as a result of community action to secure new sources of health care in the area. EBMP has a contract with the Maryland Medical Assistance Program to provide services to enrolled Medicaid recipients on a capitation basis. At the time of the study, the Public Health Service funds it received supported the entire cost of services to eligible individuals registered with the Plan. When the sample was selected in November 1973, EBMP had approximately 1,900 Medicaid enrollees, 1,880 PHS registrants, and 300 fee-for-service registrants. Data for this study were collected through household interviews conducted in the spring and summer of 1974 in three different random samples of households in 12 census tracts immediately surrounding The Johns Hopkins Hospital. The three samples, each containing approximately 550 households, were defined as follows: (a) The EBMP sample contained households of registrants and enrollees drawn from the Plan's membership list.* Information was obtained on non-members in the households as well as EBMP members. (b) The housing projects sample was drawn from households in four public housing projects in the community. The majority of EBMP members live in these projects, but the households in this sample were selected to contain no EBMP members. (c) The community sample consisted of households in the 12 census-tract areas that were not located in the housing projects and that contained no EBMP members. A total of 1,455 household interviews were completed: the completion rates were 86 per cent in the community sample, 90 per cent in the EBMP sample, and 91 per cent in the housing projects sample. The adults aged 18 through 64 in the study were categorized by per capita annual income and reported Medicaid enrollment into three groups: Medicaid recipients, the "near poor", and the "non-poor". The "near poor" were not covered by Medicaid and lived in households with per capita incomes of less than $2,500. The "non-poor" lived in households with per capita incomes of $2,500 or more. The median per capita income for the non-poor was $4,600 in the community sample and $4,300 in both the EBMP and housing proj*Only 2 per cent of the sample were fee-for-service registrants. 1196
Table 1-Distribution of Adulta Ages 18-64 by Medicaid/Income Level and Sample Group.
Community N
Medicaid
Near Poor Non-Poor
=
497
35.2 31.6 33.2
Housing Projects
N
=
539
73.1 21.3 5.6
EBMP N = 544
63.8 24.8 11.4
ects samples. The figure $2,500 was used as the cutting point since almost all the Medicaid recipients in this study (92 per cent to 97 per cent in each sample) had per capita incomes less than that amount. Table 1 shows the distribution of
adults 18-64 in each sample by Medicaid/income level. The non-poor in these sample populations were only marginally different from the near poor. Although the area in which this study was conducted is low income, there were households with high incomes, all of which were in the com-
munity sample. Since this study was concerned with the possible effect of the organization and financial arrangements of the East Baltimore Medical Plan on use of health services in this community, a major variable used in the analysis was the reported usual source of ambulatory care. In the community and housing projects samples, 56 per cent and 52 per cent of the adults, respectively, reported that the Johns Hopkins Hospital was their usual source of care. Other sources reported in these two samples included other hospital outpatient departments, private physicians, and a few, about 4 per cent, who reported no usual source of care. In the EBMP sample, 42 per cent of the adults reported that the East Baltimore Medical Plan was their usual source, 39 per cent went to Johns Hopkins, and 19 per cent to other places. Within each of the Medicaid/income categories, the distribution by usual source was similar, though slightly higher proportions of the nonpoor in the community and housing projects samples reported going to sources other than JHH. It should be noted that the EBMP sample contained individuals with different associations with the Plan. A household was eligible for inclusion in the sample if at least one member was enrolled or registered at the Plan. Accordingly, the EBMP sample contains individuals in households of members who were not themselves enrolled or registered. Limited to enrollees and registrants, the proportions reporting the Plan to be their usual source are 79 per cent and 50 per cent respectively. Most of the non-members (62 per cent) gave JHH as their usual source. Volume of health services used was measured by whether any visits to a health practitioner had been made during the six months prior to the interview. Selected circumstances for which care might be sought were examined also. These included care received for a reported episode of illness, and regular care for a chronic condition, high blood pressure. In addition, since it was possible that Medicaid recipients had more health problems than those not on Medi-
A1JPH December 1978, Vol. 68, No. 12
USE OF HEALTH SERVICES BY NEAR POOR
TABLE 2-Per Cent of Adults Ages 18-64 with No Visits in Last 6 Months by Medicaid/income Level and Sample Group Housing Projects
Community
Medicaid Near Poor
Non-Poor
EBMP
25.4
22.6
4(169)
20.5
(389)
*(332)
45.6 (147) 43.7
41.1 (112) 32.1
40.0 (130) 33.9
(158)
(28)
(56)
*These proportions are significantly different at p < .01. N. B. Small numbers of people with missing data are excluded. Note: Numbers are shown in parentheses.
caid and that sicker people might tend to join EBMP, a measure of health status was developed and used as a control variable in examining use. People were defined as in "good health" if they reported no chronic conditions or symptoms, had not had an episode of illness in the previous three months, and had no difficulty performing the following activities: walking, using stairs or inclines, stooping, crouching or kneeling; or carrying light or heavy weights. Those who had one or more of these problems were classified as in "poor" health.
Results Utilization of Services The proportion of people in each sample who reported that they had made no visits to a health practitioner in the previous six months was 38 per cent in the community sample and 27 per cent in both the housing projects and
EBMP samples. As shown in Table 2, the highest proportions of adults with no visits were found among the near poor in all three samples: between 40 per cent and 46 per cent of the near poor reported no visits, compared to 21 per cent to 25 per cent of the Medicaid recipients, and 34 per cent to 44 per cent of the non-poor. Sizable differences in the proportions of non-users between the Medicaid recipients and the near poor persisted when examined by usual source of care except among those in the EBMP sample who identified EBMP as their usual source (Table 3). Here, the difference was only 4 per cent; differences in the other sample-source groups ranged from 12 per cent to 38 per cent. Mean numbers of visits during the six-month period were consistently lower among the near poor than among the Medicaid recipients, and usually lower than among the nonpoor, regardless of the usual source of care (Table 4). The difference between the Medicaid recipients and the near poor was smaller for people whose usual source of care was EBMP than for all other groups except other source users in the housing projects sample. It is of interest to note that, among both the near poor and the Medicaid recipients, those whose usual source was EBMP had somewhat lower proportions of non-users and higher mean numbers of visits than those who used JHH. The possibility that the differences in utilization rates between Medicaid recipients and the near poor were the result of differences in the age/sex distributions was explored by adjusting the mean number of visits for each Medicaid income category to the age and sex distributions in each sample as a whole. Differences between the unadjusted and the adjusted means were small, indicating that variations in the age or sex distributions were not the basis for the observed differences among the Medicaid income groups. Another concern was that the high visit rate for the Medicaid recipients among the EBMP users may have resulted from a disproportionately large group of medically indigent individuals. These people, who are covered by Medicaid but not welfare, have a demonstrated need for health
TABLE 3-Per Cent of Adults Ages 18-64 with No Visits in Last 6 Months by Medicaid/income Level, Usual Source of Ambulatory Care and Sample Group Community JHH
Medicaid Near Poor Non-Poor
Housing Projects
Other Source
JHH
Other Source
EBMP
EBMP
JHH
Other Source
28.7
19.7
23.8
21.4
18.8
22.0
21.5
(108)
(61)
(202)
(187)
(144)
(123)
(65)
47.5
33.3
23.1
59.3
33.3
(61 )
(51)
(52)
(54)
(24)
50.6
(87)
52.2 (69)
38.3
(60)
37.1 (89)
L
41.7 (12)
25.0 (16)
27.8 (23)
L
40.0 (25)
t
*These proportions are significantly different at p < .05. **These proportions are significantly different at p < .01. tDenominator is less than 10. Note: Numbers are shown in parentheses.
AJPH December 1978, Vol. 68, No. 12
1197
SKINNER, ET AL.
TABLE 4-Mean Number of Visits In Last 6 Months among Adults Ages 18-84 by Medicaid/ Income Level, Usual Source of Ambulatory Care and Sample Group Community
Housing Projects
Other
Medicaid Near Poor
Other JHH
Other Source
3.37
2.63
2.66
(144)
(123)
JHH
Source
JHH
2.57 (108) 1.37
3.25 (61) 2.07
2.51
2.93
(202)
(187)
1.54
2.39
2.46
1.06
1.75
(54)
(24) t
(87)
Non-Poor
EBMP
(60)
1.28 (69)
2.12 (89)
Source
(61)
(51)
1.33 (12)
2.88 (16)
EBMP
(52)
2.74 (23)
1.32
(65)
(25)
tDenominator is less than 10.
Note: Numbers are shown in parentheses.
care and would be expected to be frequent users of services. However, the proportions of medically indigent individuals were similar in all the usual source groups indicating that this was not a problem. An additional factor known to affect use of services, health status, is examined in the following section.
The importance of introducing the variable of health status is underlined by the differences in proportions classified as in good health when comparisons are made by usual source of care. In the community and housing project sam-
ples, each Medicaid/income group identifying with JHH had a higher proportion in "good health" than the group associated with other providers. The selectivity that this suggests carries over to the EBMP sample as well: within this group, JHH users had higher proportions in "good health" than EBMP users or users of other sources. Accordingly, the stronger inferences in this paper relate to the data that take into account a chronic condition, an episode of illness, or a general measure of health status. Examination of utilization for each of the health status categories showed a clear pattern for the near poor to have higher proportions of non-users than did the Medicaid recipients (Table 5). This pattern is particularly evident among the JHH users, where the differences ranged from 15 per cent to
Health Status The proportions of adults aged 18-64 in the "good health" category were similar among the 3 samples: 27 per cent in the housing projects sample, 28 per cent in the EBMP sample, and 30 per cent in the community sample. As expected, the Medicaid recipients in all three samples had appreciably smaller proportions in good health, compared to the near poor. This reflects to some extent the fact that need for health care is taken into consideration in establishing eligibility for Medicaid for people with incomes above certain levels.
TABLE 5-Per Cent of Adults Ages 18-64 with No Visits In Last 6 Months by Medicaid/income Level, Health Status, Usual Source of Ambulatory Care and Sample Group Community JHH
Good Health Medicaid
Housing Projects
Other Source
Near Poor
% 48.1 (27) 63.2
% 70.0 (10) 47.1
Non-Poor
72.0
(38) (25)
66.7
Near Poor
[ 22.8 (79) [ 40.4
[ 9.8 (51) [ 34.1
Non-Poor
41.9
(47) (43)
29.0
Poor Health Medicaid
*
Other
*
EBMP
JHH
Source
% 49.0 (51) 68.0
% 36.6 (41) 47.4
% 34.8 (23) 41.7
% [ 38.5 ** (26) 70.6
% 40.9 (22) t
(25)
(19)
(12)
[ 15.2 (145) 33.3
16.8 (143) 25.8
14.7 (116) 17.5
(31) (12)
17.6
t
**
Other
Source
JHH
(17) (18)
(41) (69)
EBMP
(36)
45.5 (1 1)
t
25.0
(34)
t
(40) (17)
*
t
t
[ 16.8 (95) 40.0
11.9 (42) 17.6
(20) (16)
(17)
31.3
t
*These proportions are significantly different at p < .05. "These proportions are significantly different at p < .01.
tDenominator is less than 10.
Note: Numbers are shown in parentheses.
1198
AJPH December 1978, Vol. 68, No. 12
USE OF HEALTH SERVICES BY NEAR POOR TABLE 6-Mean Number of Visits In Last 6 Months among Adufts Ages 18-64 by Medicaid/ Income Level, Heafth Status, Usual Source of Ambulatory Care and Sample Group Community
Housing Projects
Other
Good Health Medicaid
EBMP
Other
Other
JHH
Source
JHH
Source
EBMP
JHH
Source
1.04
0.90
1.37
2.70
1.69
1.64
(51)
(51)
(23)
(26)
Near Poor
0.50
Non-Poor
0.64
1.70 (1 0) 0.82 (17) 0.50
(25)
(18)
3.00
3.55
3.08
(79)
(51)
(145)
2.50
2.05
(36) 1.36 (1 1)
(31) 3.50 (12)
(40) 3.47 (17)
1.63
(27)
(38) Poor Health Medicaid
NearPoor
2.09
2.66
Non-Poor
(47) 1.63 (43)
(41) 2.59 (69)
2.33 (12) t
0.47
(22) t
(34) t
t
3.66
3.46
2.92
(143)
(116)
(95)
3.14 (42) 2.24
(20)
(17) t
0.68
1.00
(25) t
(19) t
2.14
3.26
(16)
tDenominator is less than 10. Note: Numbers are shown in parentheses.
32 per cent. The differences between Medicaid recipients and the near poor were greater for individuals in poor health, and were statistically significant among JHH users in all three samples. The smallest differences however, were found among EBMP users in both health status groups. Mean number of visits were examined for each of the health status categories as well. Following the pattern described earlier, the means were consistently higher for Medicaid recipients regardless of health status (Table 6). The differences between means for Medicaid recipients and the near poor were generally greater among those in poor health than among those in good health. Among both Medicaid recipients and the near poor in good health, those who used EBMP had smaller proportions of non-utilizers than did those in any of the other usual source groups. A similar pattern is seen for mean numbers of visits: both Medicaid recipients and the near poor who used EBMP had the highest means of all the usual source groups in the "good health" category, 2.7 and 2.3, respectively, compared to between 0.5 and 1.7 in the other groups. This was not the case in the "poor health" category, suggesting that the differences seen previously between EBMP users and users of JHH and other sources may reflect differences in the kinds of services received rather than their volume. The data presented above indicate that utilization by adults in these samples was associated with Medicaid/income level, usual source of ambulatory care, and health status. To explore the nature of these relationships when other factors are taken into account, an analysis was undertaken using multiple linear regression. The measure of utilization used as the dependent variable was the square root of the reported number of ambulatory visits made in the previous six months.* Separate regressions were computed for each of the three samples. Table 7 lists the independent variables, all of which were dichotomous except age and the physical activity limitation AMJPH December 1978, Vol. 68, No. 12
scale** which were continuous. For the variables that were
originally trichotomous (usual source of care and Medicaid/ income level), each category was made a single dichotomous variable and one of the three categories was deleted. The deleted categories were JHH for the usual source of care, and Medicaid coverage for Medicaid/income level. The B coefficients show the estimate of the average change in the dependent variable associated with the difference between a given category and the deleted one. As can be seen in Table 8, the variables most highly correlated with use were the three that made up the health status measure: the presence of one or more chronic conditions, an episode of illness, and greater disability were all strongly associated with greater use.*** The proportion of the variance explained by these three variables was 18 per cent in the community sample, 17 per cent in the housing projects sample, and 13 per cent in the EBMP sample. In the housing projects and EBMP samples, use by Medicaid recipients (the deleted category) was significantly greater than for the near poor. The significant F value in the EBMP sample reflects the inclusion of JHH and other source users in the regression. In the community sample, the F value was significant at the .075 level, and the B coefficient is in the same direction (negative) as in the other samples. *The square root was used rather than the actual number of visits because of the extreme skewness of the distribution. **The physical activity limitation scale is based on reported difficulty in performing the following activities: walking; using stairs or inclines; stooping, crouching or kneeling; lifting or carrying light weights; and lifting or carrying heavy weights. It is a simple additive scale with a range of 0 to 5, with 0 indicating no limitations and 5 indicating limitations in all of these activities. ***Multicolinearity was not a problem among the three health variables. The highest correlation was .41 between having an episode of illness and the physical activity limitation scale in the community sample. 1199
SKINNER, ET AL. TABLE 7-Definitions of Independent Variables Used in Regression Analysis Type of Variable
Name of Variable
Demographic
Age Sex Conditions
Continuous (18-64) 1 if person is male = 1 if person has 1 or more chronic
Episode
= 1 if person had an episode of illness
Health Measures
Definition =
conditions
PAS
Medicaid/Income Level Usual Source
Near Poor Non-Poor Other
= =
EBMP*
=
=
in previous 3 months Physical Activity Scale (range is 0-5, with 0 = no disability); continuous 1 if person is in near poor category 1 if person is in non-poor category 1 if person's usual source is other than JHH (or EBMP) 1 if person's usual source is EBMP
*This variable is included in the regression for the EBMP sample only.
For the usual source variables, JHH was the deleted category. Within each of the three samples, the comparison between JHH and other sources was not significant. The source variable "EBMP" in the EBMP sample, however, was significant at the .05 level, indicating the EBMP users had higher use than JHH users when other factors were controlled. This confirms the pattern seen particularly in Tables 5 and 6, where EBMP users had lower proportions of nonusers and higher mean numbers of visits than did JHH users in the same sample.
bers were small but, in all three samples, there appeared little difference between the Medicaid recipients and the near poor in the proportion having seen a health practitioner for an episode; differences among the sources of care were also small. Health care received for chronic health problems usually requires periodic visits to health practitioners and thus differs from acute episode care. Care received for several types of chronic conditions (among which was high blood pressure) was probed in the household interview. People reporting high blood pressure were asked whether they were receiving care at regular intervals for that condition. About 26 per cent of the adults in each sample reported having high blood pressure, and between 57 per cent and 65 per cent of these said they were receiving regular care. As shown in Table 9, in almost all cases those on Medicaid were more likely to be under regular care than were the near poor. The difference between the Medicaid recipients and the near poor in the proportions under regular care was substantially smaller for EBMP users (only 2 per cent) than for the other
Episodic and Chronic Care Additional analyses were undertaken for care received for two specific types of health problems, episodes of illness and a chronic condition, high blood pressure. An episode of illness was defined as a health problem that resulted in two or more days of bed rest or restricted activity within the previous three months. About 15 per cent of the adults in each sample reported an episode of illness, and about one-half of these reported seeing a health professional for it. The num-
TABLE 8-Regression Results: Dependent Variable is Square Root of Utilization Community B
Age Sex
Conditions Episode PAS Near Poor Non-Poor Other EBMP Constant
R2 N
-0.001 0.092 0.443 0.462 0.112 -0.191 -0.180 0.162 -
Housing Projects F
0.048 1.094 21.820*** 19.437*** 10.369*** 3.159 2.628 3.377 -
0.041 0.241 462
B
0.006 0.131 0.384 0.457 0.083 -0.250 -0.126 0.128 -
-0.085 0.206*** 518
F
2.846 1.711 17.885*** 22.047*** 6.838** 6.030* 0.477 2.476 -
EBMP B
-0.003 0.172 0.434 0.339 0.104 -0.214
-0.065 0.202 0.213 0.237 0.200*** 509
F
0.826 3.370 21.080***
12.127*** 9.320***
4.604* 0.234 3.103 5.578*
*F is significant at the < .05 level **F is significant at the
Abstract: Individuals in the gray area between Medicaid eligibility and sufficient income to meet the costs of health care, the near poor, utilize health services less than other groups. As part of a study of health care behavior in an inner-city area based on a household survey of three distinct populations (HMO members, public housing project residents, and a defined geographic area), we examined this question more thoroughly. Survey results show that the near poor had lower levels of use than Medicaid recipients when other factors were controlled. Particularly among those classi-
fied as in poor health, the near poor were more likely to be non-users and less likely to make multiple visits. However, differences in use between the near poor and the Medicaid recipients are substantially and consistently smaller for the HMO users (whose costs were covered by a special contract) than for users of a hospital outpatient department. The patterns persist for regular care received for a chronic condition but not for care sought for episodes of illness. These findings point to the special disadvantage faced by low income individuals who are not receiving Medicaid. (Am. J. Public Health 68:1195-1201, 1978.)
There is growing evidence that the Medicaid program has resulted in a substantial narrowing of the gap in ambulatory health services utilization between the poor and those with considerably higher incomes. Between 1964 (the year prior to passage of legislation authorizing Medicare and Medicaid) and 1971, the ambulatory visit rate increased by almost 60 per cent among the poor to reach 5.8 visits per person per year while it remained stationary at about 5.4 among those in high income families. 1 2 This increased utilization rate seems to be indicative that the poor are receiving more needed services. Much of the increase has been attributed to the Medicaid program's reduction in economic barriers to health services for covered individuals.3-5 It is relevant to the appraisal of the effect of publicly funded programs to find that the segment of the population with low family incomes but not eligible for Medicaid, the "near poor", has failed to show increased service utilization
to the extent found in the poor. Data from the Health Interview Survey revealed that in 1964 physician visit rates were 3.7 for people in families with annual incomes below $2,000, and 4.1 for those in families with incomes between $2,000 and $3,999.1 By 1971, people in families with incomes less than $3,000 made 5.8 visits per person per year, an increase of 2.1 visits, while those with family incomes between $3,000 and $4,999 increased their rate only to 4.9 visits per person per year,2 an increase of 0.8 visits. This report delves more deeply into the use of ambulatory health care services among the near poor and considers the influence of options for such care available within a community. One option is a prepaid group practice (health maintenance program) which receives Public Health Service (Title 314e) funds to cover the cost of services to low income individuals ineligible for Medicaid. Other options include a large teaching hospital outpatient department (OPD). The experience examined relates to near poor adults aged 18-64 years who live in East Baltimore, a low-income, predominantly black community in the City of Baltimore. This age group has been studied because it is the target of relatively few altemative programs to reduce problems of access to care comparable to those available to children through C & Y (Children and Youth) projects and to the elderly through Medicare.
From the Health Services Research and Development Center, Johns Hopkins Medical Institutions. Address reprint requests to Elizabeth A. Skinner, MSW, Research Associate, Health Services Research and Development Center, Johns Hopkins Medical Institutions, 624 N. Broadway, Baltimore, MD 21205. This paper, submitted to the Journal January 18, 1978, was revised and accepted for publication April 28, 1978.
AJPH December 1978, Vol. 68, No. 12
1195
SKINNER, ET AL.
Study Background and Methods As in similar inner-city areas throughout the country, the primary sources of ambulatory care in East Baltimore are hospital outpatient departments and emergency rooms. In this particular community there is one predominant provider, the Johns Hopkins Hospital (JHH). When this study was undertaken in 1974, its OPD was providing services through a traditional arrangement of general medical and specialty clinics staffed by interns, residents, fellows, and attending physicians. Generally, all services provided through the OPD are on a fee-for-service basis. It is possible for individuals to receive services free of charge, but this involves a lengthy application and review process. The East Baltimore Medical Plan (EBMP), which began offering services in November 1971, was developed as a result of community action to secure new sources of health care in the area. EBMP has a contract with the Maryland Medical Assistance Program to provide services to enrolled Medicaid recipients on a capitation basis. At the time of the study, the Public Health Service funds it received supported the entire cost of services to eligible individuals registered with the Plan. When the sample was selected in November 1973, EBMP had approximately 1,900 Medicaid enrollees, 1,880 PHS registrants, and 300 fee-for-service registrants. Data for this study were collected through household interviews conducted in the spring and summer of 1974 in three different random samples of households in 12 census tracts immediately surrounding The Johns Hopkins Hospital. The three samples, each containing approximately 550 households, were defined as follows: (a) The EBMP sample contained households of registrants and enrollees drawn from the Plan's membership list.* Information was obtained on non-members in the households as well as EBMP members. (b) The housing projects sample was drawn from households in four public housing projects in the community. The majority of EBMP members live in these projects, but the households in this sample were selected to contain no EBMP members. (c) The community sample consisted of households in the 12 census-tract areas that were not located in the housing projects and that contained no EBMP members. A total of 1,455 household interviews were completed: the completion rates were 86 per cent in the community sample, 90 per cent in the EBMP sample, and 91 per cent in the housing projects sample. The adults aged 18 through 64 in the study were categorized by per capita annual income and reported Medicaid enrollment into three groups: Medicaid recipients, the "near poor", and the "non-poor". The "near poor" were not covered by Medicaid and lived in households with per capita incomes of less than $2,500. The "non-poor" lived in households with per capita incomes of $2,500 or more. The median per capita income for the non-poor was $4,600 in the community sample and $4,300 in both the EBMP and housing proj*Only 2 per cent of the sample were fee-for-service registrants. 1196
Table 1-Distribution of Adulta Ages 18-64 by Medicaid/Income Level and Sample Group.
Community N
Medicaid
Near Poor Non-Poor
=
497
35.2 31.6 33.2
Housing Projects
N
=
539
73.1 21.3 5.6
EBMP N = 544
63.8 24.8 11.4
ects samples. The figure $2,500 was used as the cutting point since almost all the Medicaid recipients in this study (92 per cent to 97 per cent in each sample) had per capita incomes less than that amount. Table 1 shows the distribution of
adults 18-64 in each sample by Medicaid/income level. The non-poor in these sample populations were only marginally different from the near poor. Although the area in which this study was conducted is low income, there were households with high incomes, all of which were in the com-
munity sample. Since this study was concerned with the possible effect of the organization and financial arrangements of the East Baltimore Medical Plan on use of health services in this community, a major variable used in the analysis was the reported usual source of ambulatory care. In the community and housing projects samples, 56 per cent and 52 per cent of the adults, respectively, reported that the Johns Hopkins Hospital was their usual source of care. Other sources reported in these two samples included other hospital outpatient departments, private physicians, and a few, about 4 per cent, who reported no usual source of care. In the EBMP sample, 42 per cent of the adults reported that the East Baltimore Medical Plan was their usual source, 39 per cent went to Johns Hopkins, and 19 per cent to other places. Within each of the Medicaid/income categories, the distribution by usual source was similar, though slightly higher proportions of the nonpoor in the community and housing projects samples reported going to sources other than JHH. It should be noted that the EBMP sample contained individuals with different associations with the Plan. A household was eligible for inclusion in the sample if at least one member was enrolled or registered at the Plan. Accordingly, the EBMP sample contains individuals in households of members who were not themselves enrolled or registered. Limited to enrollees and registrants, the proportions reporting the Plan to be their usual source are 79 per cent and 50 per cent respectively. Most of the non-members (62 per cent) gave JHH as their usual source. Volume of health services used was measured by whether any visits to a health practitioner had been made during the six months prior to the interview. Selected circumstances for which care might be sought were examined also. These included care received for a reported episode of illness, and regular care for a chronic condition, high blood pressure. In addition, since it was possible that Medicaid recipients had more health problems than those not on Medi-
A1JPH December 1978, Vol. 68, No. 12
USE OF HEALTH SERVICES BY NEAR POOR
TABLE 2-Per Cent of Adults Ages 18-64 with No Visits in Last 6 Months by Medicaid/income Level and Sample Group Housing Projects
Community
Medicaid Near Poor
Non-Poor
EBMP
25.4
22.6
4(169)
20.5
(389)
*(332)
45.6 (147) 43.7
41.1 (112) 32.1
40.0 (130) 33.9
(158)
(28)
(56)
*These proportions are significantly different at p < .01. N. B. Small numbers of people with missing data are excluded. Note: Numbers are shown in parentheses.
caid and that sicker people might tend to join EBMP, a measure of health status was developed and used as a control variable in examining use. People were defined as in "good health" if they reported no chronic conditions or symptoms, had not had an episode of illness in the previous three months, and had no difficulty performing the following activities: walking, using stairs or inclines, stooping, crouching or kneeling; or carrying light or heavy weights. Those who had one or more of these problems were classified as in "poor" health.
Results Utilization of Services The proportion of people in each sample who reported that they had made no visits to a health practitioner in the previous six months was 38 per cent in the community sample and 27 per cent in both the housing projects and
EBMP samples. As shown in Table 2, the highest proportions of adults with no visits were found among the near poor in all three samples: between 40 per cent and 46 per cent of the near poor reported no visits, compared to 21 per cent to 25 per cent of the Medicaid recipients, and 34 per cent to 44 per cent of the non-poor. Sizable differences in the proportions of non-users between the Medicaid recipients and the near poor persisted when examined by usual source of care except among those in the EBMP sample who identified EBMP as their usual source (Table 3). Here, the difference was only 4 per cent; differences in the other sample-source groups ranged from 12 per cent to 38 per cent. Mean numbers of visits during the six-month period were consistently lower among the near poor than among the Medicaid recipients, and usually lower than among the nonpoor, regardless of the usual source of care (Table 4). The difference between the Medicaid recipients and the near poor was smaller for people whose usual source of care was EBMP than for all other groups except other source users in the housing projects sample. It is of interest to note that, among both the near poor and the Medicaid recipients, those whose usual source was EBMP had somewhat lower proportions of non-users and higher mean numbers of visits than those who used JHH. The possibility that the differences in utilization rates between Medicaid recipients and the near poor were the result of differences in the age/sex distributions was explored by adjusting the mean number of visits for each Medicaid income category to the age and sex distributions in each sample as a whole. Differences between the unadjusted and the adjusted means were small, indicating that variations in the age or sex distributions were not the basis for the observed differences among the Medicaid income groups. Another concern was that the high visit rate for the Medicaid recipients among the EBMP users may have resulted from a disproportionately large group of medically indigent individuals. These people, who are covered by Medicaid but not welfare, have a demonstrated need for health
TABLE 3-Per Cent of Adults Ages 18-64 with No Visits in Last 6 Months by Medicaid/income Level, Usual Source of Ambulatory Care and Sample Group Community JHH
Medicaid Near Poor Non-Poor
Housing Projects
Other Source
JHH
Other Source
EBMP
EBMP
JHH
Other Source
28.7
19.7
23.8
21.4
18.8
22.0
21.5
(108)
(61)
(202)
(187)
(144)
(123)
(65)
47.5
33.3
23.1
59.3
33.3
(61 )
(51)
(52)
(54)
(24)
50.6
(87)
52.2 (69)
38.3
(60)
37.1 (89)
L
41.7 (12)
25.0 (16)
27.8 (23)
L
40.0 (25)
t
*These proportions are significantly different at p < .05. **These proportions are significantly different at p < .01. tDenominator is less than 10. Note: Numbers are shown in parentheses.
AJPH December 1978, Vol. 68, No. 12
1197
SKINNER, ET AL.
TABLE 4-Mean Number of Visits In Last 6 Months among Adults Ages 18-84 by Medicaid/ Income Level, Usual Source of Ambulatory Care and Sample Group Community
Housing Projects
Other
Medicaid Near Poor
Other JHH
Other Source
3.37
2.63
2.66
(144)
(123)
JHH
Source
JHH
2.57 (108) 1.37
3.25 (61) 2.07
2.51
2.93
(202)
(187)
1.54
2.39
2.46
1.06
1.75
(54)
(24) t
(87)
Non-Poor
EBMP
(60)
1.28 (69)
2.12 (89)
Source
(61)
(51)
1.33 (12)
2.88 (16)
EBMP
(52)
2.74 (23)
1.32
(65)
(25)
tDenominator is less than 10.
Note: Numbers are shown in parentheses.
care and would be expected to be frequent users of services. However, the proportions of medically indigent individuals were similar in all the usual source groups indicating that this was not a problem. An additional factor known to affect use of services, health status, is examined in the following section.
The importance of introducing the variable of health status is underlined by the differences in proportions classified as in good health when comparisons are made by usual source of care. In the community and housing project sam-
ples, each Medicaid/income group identifying with JHH had a higher proportion in "good health" than the group associated with other providers. The selectivity that this suggests carries over to the EBMP sample as well: within this group, JHH users had higher proportions in "good health" than EBMP users or users of other sources. Accordingly, the stronger inferences in this paper relate to the data that take into account a chronic condition, an episode of illness, or a general measure of health status. Examination of utilization for each of the health status categories showed a clear pattern for the near poor to have higher proportions of non-users than did the Medicaid recipients (Table 5). This pattern is particularly evident among the JHH users, where the differences ranged from 15 per cent to
Health Status The proportions of adults aged 18-64 in the "good health" category were similar among the 3 samples: 27 per cent in the housing projects sample, 28 per cent in the EBMP sample, and 30 per cent in the community sample. As expected, the Medicaid recipients in all three samples had appreciably smaller proportions in good health, compared to the near poor. This reflects to some extent the fact that need for health care is taken into consideration in establishing eligibility for Medicaid for people with incomes above certain levels.
TABLE 5-Per Cent of Adults Ages 18-64 with No Visits In Last 6 Months by Medicaid/income Level, Health Status, Usual Source of Ambulatory Care and Sample Group Community JHH
Good Health Medicaid
Housing Projects
Other Source
Near Poor
% 48.1 (27) 63.2
% 70.0 (10) 47.1
Non-Poor
72.0
(38) (25)
66.7
Near Poor
[ 22.8 (79) [ 40.4
[ 9.8 (51) [ 34.1
Non-Poor
41.9
(47) (43)
29.0
Poor Health Medicaid
*
Other
*
EBMP
JHH
Source
% 49.0 (51) 68.0
% 36.6 (41) 47.4
% 34.8 (23) 41.7
% [ 38.5 ** (26) 70.6
% 40.9 (22) t
(25)
(19)
(12)
[ 15.2 (145) 33.3
16.8 (143) 25.8
14.7 (116) 17.5
(31) (12)
17.6
t
**
Other
Source
JHH
(17) (18)
(41) (69)
EBMP
(36)
45.5 (1 1)
t
25.0
(34)
t
(40) (17)
*
t
t
[ 16.8 (95) 40.0
11.9 (42) 17.6
(20) (16)
(17)
31.3
t
*These proportions are significantly different at p < .05. "These proportions are significantly different at p < .01.
tDenominator is less than 10.
Note: Numbers are shown in parentheses.
1198
AJPH December 1978, Vol. 68, No. 12
USE OF HEALTH SERVICES BY NEAR POOR TABLE 6-Mean Number of Visits In Last 6 Months among Adufts Ages 18-64 by Medicaid/ Income Level, Heafth Status, Usual Source of Ambulatory Care and Sample Group Community
Housing Projects
Other
Good Health Medicaid
EBMP
Other
Other
JHH
Source
JHH
Source
EBMP
JHH
Source
1.04
0.90
1.37
2.70
1.69
1.64
(51)
(51)
(23)
(26)
Near Poor
0.50
Non-Poor
0.64
1.70 (1 0) 0.82 (17) 0.50
(25)
(18)
3.00
3.55
3.08
(79)
(51)
(145)
2.50
2.05
(36) 1.36 (1 1)
(31) 3.50 (12)
(40) 3.47 (17)
1.63
(27)
(38) Poor Health Medicaid
NearPoor
2.09
2.66
Non-Poor
(47) 1.63 (43)
(41) 2.59 (69)
2.33 (12) t
0.47
(22) t
(34) t
t
3.66
3.46
2.92
(143)
(116)
(95)
3.14 (42) 2.24
(20)
(17) t
0.68
1.00
(25) t
(19) t
2.14
3.26
(16)
tDenominator is less than 10. Note: Numbers are shown in parentheses.
32 per cent. The differences between Medicaid recipients and the near poor were greater for individuals in poor health, and were statistically significant among JHH users in all three samples. The smallest differences however, were found among EBMP users in both health status groups. Mean number of visits were examined for each of the health status categories as well. Following the pattern described earlier, the means were consistently higher for Medicaid recipients regardless of health status (Table 6). The differences between means for Medicaid recipients and the near poor were generally greater among those in poor health than among those in good health. Among both Medicaid recipients and the near poor in good health, those who used EBMP had smaller proportions of non-utilizers than did those in any of the other usual source groups. A similar pattern is seen for mean numbers of visits: both Medicaid recipients and the near poor who used EBMP had the highest means of all the usual source groups in the "good health" category, 2.7 and 2.3, respectively, compared to between 0.5 and 1.7 in the other groups. This was not the case in the "poor health" category, suggesting that the differences seen previously between EBMP users and users of JHH and other sources may reflect differences in the kinds of services received rather than their volume. The data presented above indicate that utilization by adults in these samples was associated with Medicaid/income level, usual source of ambulatory care, and health status. To explore the nature of these relationships when other factors are taken into account, an analysis was undertaken using multiple linear regression. The measure of utilization used as the dependent variable was the square root of the reported number of ambulatory visits made in the previous six months.* Separate regressions were computed for each of the three samples. Table 7 lists the independent variables, all of which were dichotomous except age and the physical activity limitation AMJPH December 1978, Vol. 68, No. 12
scale** which were continuous. For the variables that were
originally trichotomous (usual source of care and Medicaid/ income level), each category was made a single dichotomous variable and one of the three categories was deleted. The deleted categories were JHH for the usual source of care, and Medicaid coverage for Medicaid/income level. The B coefficients show the estimate of the average change in the dependent variable associated with the difference between a given category and the deleted one. As can be seen in Table 8, the variables most highly correlated with use were the three that made up the health status measure: the presence of one or more chronic conditions, an episode of illness, and greater disability were all strongly associated with greater use.*** The proportion of the variance explained by these three variables was 18 per cent in the community sample, 17 per cent in the housing projects sample, and 13 per cent in the EBMP sample. In the housing projects and EBMP samples, use by Medicaid recipients (the deleted category) was significantly greater than for the near poor. The significant F value in the EBMP sample reflects the inclusion of JHH and other source users in the regression. In the community sample, the F value was significant at the .075 level, and the B coefficient is in the same direction (negative) as in the other samples. *The square root was used rather than the actual number of visits because of the extreme skewness of the distribution. **The physical activity limitation scale is based on reported difficulty in performing the following activities: walking; using stairs or inclines; stooping, crouching or kneeling; lifting or carrying light weights; and lifting or carrying heavy weights. It is a simple additive scale with a range of 0 to 5, with 0 indicating no limitations and 5 indicating limitations in all of these activities. ***Multicolinearity was not a problem among the three health variables. The highest correlation was .41 between having an episode of illness and the physical activity limitation scale in the community sample. 1199
SKINNER, ET AL. TABLE 7-Definitions of Independent Variables Used in Regression Analysis Type of Variable
Name of Variable
Demographic
Age Sex Conditions
Continuous (18-64) 1 if person is male = 1 if person has 1 or more chronic
Episode
= 1 if person had an episode of illness
Health Measures
Definition =
conditions
PAS
Medicaid/Income Level Usual Source
Near Poor Non-Poor Other
= =
EBMP*
=
=
in previous 3 months Physical Activity Scale (range is 0-5, with 0 = no disability); continuous 1 if person is in near poor category 1 if person is in non-poor category 1 if person's usual source is other than JHH (or EBMP) 1 if person's usual source is EBMP
*This variable is included in the regression for the EBMP sample only.
For the usual source variables, JHH was the deleted category. Within each of the three samples, the comparison between JHH and other sources was not significant. The source variable "EBMP" in the EBMP sample, however, was significant at the .05 level, indicating the EBMP users had higher use than JHH users when other factors were controlled. This confirms the pattern seen particularly in Tables 5 and 6, where EBMP users had lower proportions of nonusers and higher mean numbers of visits than did JHH users in the same sample.
bers were small but, in all three samples, there appeared little difference between the Medicaid recipients and the near poor in the proportion having seen a health practitioner for an episode; differences among the sources of care were also small. Health care received for chronic health problems usually requires periodic visits to health practitioners and thus differs from acute episode care. Care received for several types of chronic conditions (among which was high blood pressure) was probed in the household interview. People reporting high blood pressure were asked whether they were receiving care at regular intervals for that condition. About 26 per cent of the adults in each sample reported having high blood pressure, and between 57 per cent and 65 per cent of these said they were receiving regular care. As shown in Table 9, in almost all cases those on Medicaid were more likely to be under regular care than were the near poor. The difference between the Medicaid recipients and the near poor in the proportions under regular care was substantially smaller for EBMP users (only 2 per cent) than for the other
Episodic and Chronic Care Additional analyses were undertaken for care received for two specific types of health problems, episodes of illness and a chronic condition, high blood pressure. An episode of illness was defined as a health problem that resulted in two or more days of bed rest or restricted activity within the previous three months. About 15 per cent of the adults in each sample reported an episode of illness, and about one-half of these reported seeing a health professional for it. The num-
TABLE 8-Regression Results: Dependent Variable is Square Root of Utilization Community B
Age Sex
Conditions Episode PAS Near Poor Non-Poor Other EBMP Constant
R2 N
-0.001 0.092 0.443 0.462 0.112 -0.191 -0.180 0.162 -
Housing Projects F
0.048 1.094 21.820*** 19.437*** 10.369*** 3.159 2.628 3.377 -
0.041 0.241 462
B
0.006 0.131 0.384 0.457 0.083 -0.250 -0.126 0.128 -
-0.085 0.206*** 518
F
2.846 1.711 17.885*** 22.047*** 6.838** 6.030* 0.477 2.476 -
EBMP B
-0.003 0.172 0.434 0.339 0.104 -0.214
-0.065 0.202 0.213 0.237 0.200*** 509
F
0.826 3.370 21.080***
12.127*** 9.320***
4.604* 0.234 3.103 5.578*
*F is significant at the < .05 level **F is significant at the
