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International Journal for Equity in Health logoLink to International Journal for Equity in Health
. 2016 Aug 2;15:124. doi: 10.1186/s12939-016-0413-x

Insurance-related disparities in primary care quality among U.S. Type 2 diabetes patients

De-Chih Lee 1,2, Hailun Liang 1,3, Leiyu Shi 1,3,
PMCID: PMC4969633  PMID: 27484081

Abstract

Background

This study explored insurance-related disparities in primary care quality among Americans with type 2 diabetes.

Methods

Data came from the household component of the 2012 Medical Expenditure Panel Survey (MEPS). Analysis focused on adult subjects with type 2 diabetes. Logistic regressions were performed to investigate the associations between insurance status and primary care attributes related to first contact, longitudinality, comprehensiveness, and coordination, while controlling for confounding factors.

Results

Preliminary findings revealed differences among three insurance groups in the first contact domain of primary care quality. After controlling for confounding factors, these differences were no longer apparent, with all insurance groups reporting similar primary care quality according to the four domains of interest in the study. There were significant differences in socioeconomic status among different insurance groups.

Conclusion

This study reveals equitable primary care quality for diabetes patients despite their health insurance status. In addition to insurance-related differences, the other socioeconomic stratification factors are assumed to be the root cause of disparities in care. This research emphasizes the crucial role that primary care plays in the accessibility and quality of care for chronically ill patients. Policy makers should continue their commitment to reduce gaps in insurance coverage and improve access as well as quality of diabetic care.

Keywords: Insurance-related disparities, Primary care quality, Diabetes

Background

Diabetes is one of the leading causes of deaths worldwide. According to the World Health Organization (WHO), around 1.5 million people worldwide died due to diabetes in 2012 [1]. In 2000, the prevalence of diabetes was about 171 million worldwide, and the WHO estimates that by 2030, the prevalence will rise to 366 million individuals [2]. In 2012, 9.3 % of the U.S. population had diabetes [3]. Diabetes is among the ten most expensive medical conditions in the U.S. [4]. The estimated diabetes costs in the U.S. in 2012 was $245 billion [3]. Diabetes is also associated with many health complications if preventive care and proper treatment is not received, including renal disease, non-traumatic lower limb amputations, blindness, and increased risk for cardiovascular disease and stroke [5].

Timely access to primary care and proper adherence to clinical treatment for diabetes can reduce the risk of health complications and improve long-term health outcomes for diabetes patients. Evidence suggests that insurance coverage can greatly improve diabetes patients’ access to care, having an impact on quality of care as well as health outcomes, especially when gaps and disparities are addressed [46].

Studies have shown a significant association between diabetes quality of care and insurance coverage. A study comparing the quality of diabetes care by insurance type in federally funded community health centers in the United States gives evidence of insurance-related disparities [4]. The results showed that those without insurance were least likely to meet the quality of care measures and that those with Medicaid had quality of care similar to those with no insurance [4]. The finding of lower quality and access to care for uninsured patients is supported by another study by Hu et al. This study noted that participants with private insurance or Medicare and Medicaid coverage were more likely to receive quality diabetes care than uninsured individuals [5]. A study by Booth et al. showed the universal drug coverage can help improve outcomes for diabetes patients of lower socioeconomic status [6].

While previous literature has uncovered insurance-related disparities in diabetes care and health outcomes, little exploration has been conducted on the relationship between insurance status and primary care quality among diabetic patients. This is important, as primary care has been proven to be effective in the management of diabetes [79]. The purpose of this study is to explore insurance-related differences in primary care quality – particularly, the cardinal attributes of first contact, longitudinality, comprehensiveness, and coordination [10] - among Americans with type 2 diabetes. First contact care means that care is first sought from the primary care provider when a new health or medical need arises. Longitudinality refers to the longitudinal use of a regular source of care over time, regardless of the presence or absence of disease or injury. Comprehensiveness refers to the availability of a wide range of services in primary care and their appropriate provision across the entire spectrum of types of needs for all but the most uncommon problems in the population by a primary care provider. Coordinated care is the linking of healthcare visits and services so that patients receive appropriate care for all their health problems, physical as well as mental [10, 11].

The unique contribution of this study lies in its enhanced generalizability by using a nationally-representative sample, up-to-date information on the topic, as well as empirical evidence for tracking the impact of the Affordable Care Act (ACA) on primary care system and the benefit for chronically ill patients.

Methods

Data

Data from the household component of the 2012 Medical Expenditure Panel Survey (MEPS) was used for this study. MEPS is a nationally representative survey of the US noninstitutionalized civilian population, composed of survey data of families and individuals, their medical providers, and employers. The annual data files are released with one common variance structure, which reflects the complex sample design of the MEPS. MEPS is supported by the Agency for Healthcare Research and Quality (AHRQ) [12]. The dataset used was the most currently released version at the time this study was conducted. The 2012 MEPS contained a total of 38,974 observations; the current study included respondents aged 18 and over who reported being told by a clinician that they had diabetes. We excluded respondents who had missing value for insurance status.

Measures

The household component of MEPS collects detailed data on demographic characteristics, health conditions, health status, use of medical care services, charges and payments, access to primary care, satisfaction with care, health insurance coverage, income, and employment [12]. In this study, we selected measures of primary care attributes (dependent variables), types of health insurance (independent variable), and individual characteristics (covariates).

Following previous work conducted on primary care quality [10, 13, 14], we examined four cardinal attributes of primary care – first contact, longitudinality, comprehensiveness, and coordination – as dependent variables of interest. We selected eight measures from MEPS related to first contact attribute, which were having a usual source of care (USC) (yes, no); provider type of USC (facility, person/person in facility); provider specialty of USC (primary care, other); USC location (office, hospital); difficulty contacting USC by phone (not very difficult, very difficult); USC office hours on nights/weekends (yes, no); time to get to USC (<=30 min, >30 min); and difficulty getting to USC (not difficult, difficult). In terms of longitudinality, we used one measure of USC provider listening to patients (yes, no). For the attribute of comprehensiveness, we selected one question: going to USC for preventive health care (yes, no). Finally, two measures were selected for measuring the coordination, which were provider asking about other treatments (yes, no) and patient going to USC for referrals (yes, no).

We used Aday and Andersen’s access-to-care framework to select individual covariates that are potentially related to the primary care experience. Predisposing factors included: age (18–45, 46–64, above 64); sex (male, female); race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, Non-Hispanic Asian, Others); health insurance (public, private, no insurance); education (no degree, high school diploma, bachelor and higher degree, other); employment status (not employed, employed); income (<$20,000, $20,000–39,999, > = $40,000); and marital status (married, not married). Enabling factors included: metropolitan statistical area (MSA) (yes, no) and census region (northwest, Midwest, south, west). Need factors were: perceived health status (excellent/very good/good, fair/poor); perceived mental health status (excellent/very good/good, fair/poor); help with activities of daily living (ADL help screener) (yes, no); and help with instrumental activities of daily living (IADL help screener) (yes, no).

Analysis

We performed all the data analyses by using Stata/SE 14.0. All the analyses accounted for both the design effect and the sampling weights by using svy command. Bivariate comparisons were performed between an individual’s insurance type and primary care measures related to first contact, longitudinality, comprehensiveness, and coordination. Chi-square tests were performed to determine whether there were differences between insurance groups in primary care quality. Logistic regressions were used to examine the association between insurance types and primary care measures, while controlling for individual covariates. We also performed bivariate comparison to show the variations in socioeconomic status (education, employment status and income) among types of insurance. We used standard errors, p-values, odds ratios, and 95 % confidence intervals to interpret statistical significance and effect size.

Results

In 2012, it was estimated that more than 21.8 million Americans had type 2 diabetes. The majority of those were between the ages of 46 and 64 (44 %), and 65 and older (43 %). In terms of race/ethnicity, 60 % were non-Hispanic white, 17 % were Hispanic, 15 % were black, 5 % were Asian, and 3 % were others. Only 8 % were uninsured. 58 % were covered by private health insurance and 34 % were covered by public health insurance. Individuals with a high school diploma, the unemployed, and those with incomes below $20,000 accounted for over half of those with diabetes. About 41 % of diabetes cases were from the southern census region and 83 % were from urban areas. Table 1 shows additional information about the study population.

Table 1.

Demographic and primary care characteristics for adults with diabetes

Personal Characteristics Frequency Weighted Frequency Weighted % Standard Error (SE)
Predisposing factors
Age in years***
 18–45 403 2,924,379 13.41 0.86
 46–64 1,164 9,561,753 43.84 1.5
 Above 64 1,049 9,325,508 42.75 1.5
Sex**
 Male 1,230 11,156,923 51.15 1.2
 Female 1,387 10,656,858 48.85 1.2
Race/Ethnicity***
 Non-Hispanic White 953 13,159,194 60.33 1.7
 Non-Hispanic Black 683 3,368,274 15.44 1.1
 Hispanic 743 3,592,967 16.47 1.4
 Non-Hispanic Asian 171 1,012,791 4.64 0.55
 Others 67 680,554 3.12 0.62
Health insurance***
 Private 1,260 12,567,988 57.61 1.5
 Public 1,041 7,514,538 34.45 1.4
 No insurance 316 1,731,254 7.94 0.65
Education***
 No Degree 373 2,135,699 20.92 1.3
 High School Diploma 655 5,823,750 57.04 1.8
 Bachelor and Higher Degree 193 1,686,156 16.51 1.3
 Other 63 565,057 5.53 0.88
Employment status***
 Not employed 1,566 12,807,108 58.86 1.4
 Employed 1,046 8,952,016 41.14 1.4
Income*** *
  < $20,000 1,500 10,985,633 50.39 1.4
 $20,000–39,999 612 5,322,165 24.41 1
  > = $40,000 504 5,493,176 25.2 1.3
Marital***
 No 1,245 9,458,394 43.36 1.2
 Yes 1,372 12,355,387 56.64 1.2
Enabling factors
MSA** ***
 No 387 3,870,681 17.75 1.6
 Yes 2,229 17,940,960 82.25 1.6
Census region** ***
 Northeast 424 3,855,015 17.67 1.3
 Midwest 449 4,705,831 21.57 1.3
 South 1,109 8,893,429 40.77 1.4
 West 634 4,357,367 19.98 1.1
Need factors
Perceived health status *** ***
 Excellent/VG/Good 1,656 14,350,075 65.78 1.2
 Fair/Poor 961 7,463,705 34.22 1.2
Perceived mental health status *** ***
 Excellent/VG/Good 2,203 18,510,339 84.86 0.93
 Fair/Poor 414 3,303,441 15.14 0.93
ADL help screener *** ***
 No 2,457 20,608,010 94.47 0.64
 Yes 160 1,205,770 5.53 0.64
IADL help screener *** ***
 No 2,362 19,750,771 90.54 0.72
 Yes 255 2,063,009 9.46 0.72
Primary Care Attribute
        First Contact
Have USC ***
 No 253 1,676,213 7.81 0.75
 Yes 2,316 19,799,721 92.19 0.75
Provider type of USC ***
 Facility 1,140 8,879,718 44.85 1.71
 Person/Person in facility 1,176 10,920,003 55.15 1.71
Provider specialty of USC
 Primary care 1,066 9,727,524 89.08 1.52
 Other 110 1,192,479 10.92 1.52
USC location
 Office 1,664 15,321,478 77.48 1.44
 Hospital 648 4,453,434 22.52 1.44
Difficulty in contacting USC by phone ***
 Not very difficult 2,096 17,845,798 93.95 0.71
 Very difficult 139 1,148,599 6.05 0.71
USC has office hours nights/weekends ***
 No 1,412 12,252,897 68.91 1.44
 Yes 670 5,528,129 31.09 1.44
How long it takes get to USC ***
  ≤ 30 min 1,974 17,095,937 86.43 0.96
  > 30 min 338 2,684,740 13.57 0.96
How difficult is it get to USC
 Difficulty 2,280 19,579,459 99.03 0.23
 Not difficult 31 192,250 0.97 0.23
Longitudinality
USC provider listens
 No 28 151,190 0.81 0.19
 Yes 2,139 18,552,573 99.19 0.19
Comprehensiveness
Goes to USC for preventive health care ***
 No 24 155,285 0.79 0.20
 Yes 2,288 19,605,865 99.21 0.20
Coordination
Provider asks about other treatments
 No 379 3,188,383 16.61 1.08
 Yes 1,875 16,007,106 83.39 1.08
Goes to USC for referrals
 No 35 369,907 1.87 0.40
 Yes 2,277 19,416,969 98.13 0.40

*p < 0.05, **p < 0.01, ***p < 0.001

When looking at first contact attributes of primary care among the study population by three insurance types, 69 % of uninsured reported having a usual source of care, compared to 94 % of privately-insured and 94 % of publicly-insured (p < .001). The uninsured overwhelmingly reported a facility to be their usual source of care (62 %) compared to people under private health insurance coverage (44 %) and under public insurance coverage (43 %) (p < .01). Hospitals accounted for 31 % of USC locations among uninsured, 26 % among publicly-insured, and only 20 % among privately-insured (p < .01). About 1 % of privately-insured, 2 % of publicly-insured and 1 % of uninsured reported not difficult in getting to USC (p < .01). When looking at the other measures in first contact as well as the measures regarding the longitudinality, comprehensiveness and coordination attributes of primary care, no additional significant differences were found. Additional findings are presented in Table 2.

Table 2.

Primary care characteristics for adults with diabetes, by insurance status

Insurance
Private, % (SE) Public, % (SE) Uninsured, % (SE)
Primary Care Attribute Freq Weighted Frequency Weighted % SE Freq Weighted Frequency Weighted % SE Freq Weighted Frequency Weighted % SE
   First Contact
Have USC ***
 No 86 702,336 5.65 0.9 68 457,288 6.21 1.1 99 516,590 30.84 3.8
 Yes 1,159 11,732,932 94.35 0.9 946 6,908,250 93.79 1.1 211 1,158,539 69.16 3.8
Provider type of USC **
 Facility 542 5,184,360 44.19 2.2 454 2,982,421 43.17 2.2 144 712,937 61.54 4.7
 Person/Person in facility 617 6,548,572 55.81 2.2 492 3,925,828 56.83 2.2 67 445,603 38.46 4.7
Provider specialty of USC
 Primary care 562 5,821,805 88.9 2.1 446 3,512,108 89.46 2 58 393,611 88.33 4.5
 Other 55 726,767 11.1 2.1 46 413,720 10.54 2 9 51,992 11.67 4.5
USC location **
 Office 875 9,386,435 80.07 1.8 656 5,139,253 74.48 2 133 795,790 69.09 4.4
 Hospital 282 2,336,115 19.93 1.8 289 1,761,217 25.52 2 77 356,102 30.91 4.4
Difficulty in contacting USC by phone
 Not very difficult 1,060 10,580,584 94.5 1 861 6,263,976 93.5 1.1 175 1,001,238 91.13 2.1
 Very difficult 55 615,910 5.5 1 58 435,224 6.5 1.1 26 97,466 8.87 2.1
USC has office hours nights/weekends
 No 679 7,168,320 67.41 2 603 4,379,029 71.62 2.1 130 705,548 68.31 4.4
 Yes 373 3,465,310 32.59 2 236 1,735,547 28.38 2.1 61 327,272 31.69 4.4
How long it takes get to USC
  ≤ 30 min 1,014 10,313,811 87.9 1.4 792 5,835,272 84.49 1.4 168 946,853 82.94 3.1
  > 30 min 145 1,419,120 12.1 1.4 153 1,070,859 15.51 1.4 40 194,761 17.06 3.1
How difficult is it get to USC **
 Difficulty 1,152 11,671,618 99.49 0.24 923 6,778,351 98.25 0.43 205 1,129,490 98.94 0.69
 Not difficult 6 59,276 0.51 0.24 22 120,850 1.75 0.43 3 12,124 1.06 0.69
   Longitudinality
USC provider listens
 No 9 65,133 0.6 0.26 16 76,154 1.16 0.3 3 9,903 0.85 0.51
 Yes 1,057 10,880,003 99.4 0.26 889 6,511,449 98.84 0.3 193 1,161,121 99.15 0.51
   Comprehensiveness
Goes to USC for preventive health care
 No 8 61,016 0.52 0.21 11 79,061 1.15 0.42 5 15,208 1.32 0.69
 Yes 1,150 11,652,671 99.48 0.21 934 6,820,140 98.85 0.42 204 1,133,054 98.68 0.69
   Coordination
Provider asks about other treatments
No 183 1,833,937 16.09 1.5 154 1,155,387 17.3 1.6 42 199,060 17.83 3.3
Yes 947 9,566,148 83.91 1.5 768 5,523,532 82.7 1.6 160 917,426 82.17 3.3
Goes to USC for referrals
No 18 194,748 1.66 0.5 13 161,616 2.34 0.81 4 13,543 1.18 0.62
Yes 1,141 11,538,183 98.34 0.5 933 6,746,634 97.66 0.81 203 1,132,151 98.82 0.62

*p < 0.05, **p < 0.01, ***p < 0.001

After controlling for individual’s predisposing, enabling, and needs factors, including race/ethnicity, insurance, age, gender, employment status, education, marital status, income, health status, mental health status, having an ADL or IADL screener, MSA and region, the differences found in Table 2 were no longer significant. Table 3 shows the results of logistic regressions associating health insurance status with primary care quality according to the four domains of primary care. Model 1 shows the unadjusted odds ratios expressed as the odds of each primary care attribute among each health insurance group compared with privately-insured. Similar to the findings from Table 2, the uninsured were less likely to have USC compared with people under private insurance coverage (OR = 0.134, P < .001). The uninsured were more likely to report a facility to be their usual source of care (OR = 2.021, P < .01) and were less likely to report office as their USC locations than privately-insured (OR = 0.556, P < .001). The publicly-insured were also less likely to report an office as their USC location than privately-insured (OR = 0.726, P < .05). The publicly-insured were 3.511 times more likely to have difficulties in getting to their USC than privately-insured.

Table 3.

Logistic regressions: primary care characteristics for adults with diabetes, insurance status

Odds Ratio (95 % CI)
Model 1 Model 2
Primary Care Attribute Public vs. Private Uninsured vs Private Public vs. Private Uninsured vs Private
Have USC
 Yes 0.904 (0.557 1.467) 0.134 *** (0.081 0.222) 0.831 (0.484 1.428) 0.186 *** (0.103 0.337)
 No 1 1 1 1
Provider type of USC
 Facility 0.960 (0.774 1.189) 2.021 ** (1.317 3.100) 0.794 (0.598 1.055) 1.352 (0.863 2.118)
 Person/Person in facility 1 1 1 1
Provider specialty of USC
 Primary care 1.060 (0.614 1.828) 0.945 (0.373 2.397) 1.072 (0.550 2.087) 1.056 (0.373 2.989)
 Other 1 1 1 1
USC location
 Office 0.726 * (0.552 0.956) 0.556 ** (0.366 0.845) 0.893 (0.628 1.270) 0.797 (0.506 1.254)
 Hospital 1 1 1 1
Difficulty in contacting USC by phone
 Very difficult 1.194 (0.683 2.085) 1.672 (0.896 3.120) 0.875 (0.420 1.821) 1.234 (0.652 2.337)
 Not very difficult 1 1 1 1
USC has office hours nights/weekends
 Yes 0.820 (0.622 1.080) 0.960 (0.613 1.501) 0.915 (0.656 1.276) 0.936 (0.576 1.521)
 No 1 1 1 1
How long it takes get to USC
  ≤ 30 min 0.750 (0.524 1.073) 0.669 (0.402 1.113) 0.914 (0.598 1.396) 0.867 (0.491 1.530)
  > 30 min 1 1 1 1
How difficult is it get to USC
 Difficulty 3.511 ** (1.369 9.006) 2.113 (0.367 2.160) 1.011 (0.301 3.392) 0.905 (0.111 7.392)
 Not difficult 1 1 1 1
Longitudinality
USC provider listens
 Yes 0.512 (0.187 1.398) 0.702 (0.159 3.102) 0.742 (0.235 2.341) 1.926 (0.416 8.927)
 No 1 1 1 1
Comprehensiveness
Goes to USC for preventive health care
 Yes 0.452 (0.149 1.372) 0.390 (0.104 1.460) 0.730 (0.191 2.790) 0.478 (0.107 2.136)
 No 1 1 1 1
Coordination
Provider asks about other treatments
 Yes 0.917 (0.679 1.238) 0.884 (0.541 1.443) 0.925 (0.646 1.325) 0.887 (0.525 1.497)
 No 1 1 1 1
Goes to USC for referrals
 Yes 0.705 (0.278 1.784) 1.411 (0.407 4.888) 0.543 (0.149 1.974) 0.932 (0.233 3.735)
 No 1 1 1 1

Notes: Model 2 adjusted for race/ethnicity, insurance, age, gender, employment status, education, marital, income, health status, mental health status, ADL screener, IADL screener, MSA, and region

*p < 0.05, **p < 0.01, ***p < 0.001

Model 2 shows the results of multivariate logistic regressions. Odds ratios have been adjusted for individuals’ covariates that are potentially related to the primary care experience. After accounting for the individuals’ predisposing, enabling and need factors, the significant differences in primary care quality, which were found in Model 1, were no longer apparent. More specifically, only one insurance group, the uninsured, was still associated with lower odds in having USC (OR = 0.186, P < .001). No negative associations were found between privately-insured and primary care quality. The significant associations found in Model 1, between uninsured and higher odds of reporting a facility as their USC provider, and between uninsured and lower odds of reporting an office as their USC location, were no longer statistically significant after controlling for the confounding factors. In terms of the longitudinality, comprehensiveness and coordination attributes, there was no statistically significant association found between insurance types and primary care quality.

Table 4 shows the variations in socioeconomic status (education, employment status and income) among three types of insurance. Sixty-two percent of privately-insured reported having a high school diploma, compared to 50 % of publicly-insured and 50 % of uninsured (p < .001). Most of the publicly-insured were unemployed (89 %) compared to people under private health insurance coverage (43 %) or uninsured (42 %) (p < .001). Thirty-three percent of the privately-insured reported their income level as below $20,000, compared to 77 % of the publicly-insured and 64 % of the uninsured (p < .001).

Table 4.

Socioeconomic status (SES) for adults with diabetes, by insurance status

Private Public Uninsured
SES Weighted % SE Weighted % SE Weighted % SE
Education ***
 No Degree 9.35 1.28 36.92 2.73 35.34 4.76
 High School Diploma 62.31 2.43 49.86 3.05 49.94 5.46
 Bachelor and Higher Degree 21.17 1.96 9.85 1.63 11.26 3.07
 Other 7.17 1.28 3.37 1.13 3.47 1.65
Employment status ***
 Not employed 43.28 2.03 88.73 1.20 41.93 3.81
 Employed 56.72 2.03 11.27 1.20 58.07 3.81
Income ***
  < $20,000 32.83 1.7 76.68 2.04 64.40 4.21
 $20,000–39,999 29.30 1.46 16.73 1.61 21.98 3.26
  > = $40,000 37.88 1.80 6.59 1.19 13.62 3.36

*p < 0.05, **p < 0.01, ***p < 0.001

Discussion

The study used nationally-representative MEPS data to explore the presence of disparities in quality of primary care, and to build on past research investigating whether insurance differences in quality of care persist in an effort to eliminate health disparities over the years. The unadjusted results revealed differences in primary care quality among different insurance groups across measures in the first contact attribute. After accounting for the individuals’ predisposing, enabling and need factors, the significant differences were no longer apparent. Our study suggests that equitable primary care quality was received by diabetes patients despite their health insurance status and implies the crucial role that primary care plays in providing a more equitable level of care for patients with chronic disease.

Previous studies suggests that there were insurance-related disparities in access to primary care, the medical management of chronic illness, health care qualities and health outcomes [1517]. However, with ACA providing a solid foundation for expansions in health insurance coverage and strengthening the U.S. primary care system [18], health care disparities have been narrowed among groups with different insurance statuses. The ACA spurred major expansions in health insurance coverage, with some of the biggest gains from the federally operated marketplace and in states that expanded eligibility for their Medicaid programs. About 6.7 million people enrolled in health plans sold through the ACA’s marketplaces in 2014 [19]. Nearly 10 million people have newly enrolled in Medicaid since October 2013 [20]. Moreover, multiple provisions were included in the ACA for improving primary care, such as the support for innovation in primary care delivery, increasing Medicaid and Medicare payments to primary care providers, and investing in primary care workforce development. For chronic disease patients, the ACA advances the “medical home” concept for Medicaid patients with chronic conditions. Starting in 2011, millions of Medicaid patients with chronic conditions could have a health home to help them manage their condition. Such reforms in health insurance coverage and primary care provide a solid foundation for strengthening the U.S. primary care system, and have a positive impact on patient’s care, especially for chronically ill patients [18]. Policy makers should continue their commitment to target vulnerable groups, such as elderly, poor, and/or medically underserved populations, and reduce gaps in insurance coverage in further and therefore ultimately improving access and quality of care.

This study has several limitations. First, it is difficult to make causal inferences due to the secondary nature of the dataset. Second, MEPS data on primary care relies on household respondents’ self-report, which is subject to recall bias. Third, the study only included measures regarding primary care experience reported by the patients, rather than their health outcomes. Further studies may include more health outcomes measures, such as clinical performance indicators, to evaluate the impact of health insurance on diabetic care outcomes. Fourth, our results showed there were significant differences in socioeconomic status among major types of health insurance. The analysis could be improved to present analyses that characterize the degree to which each type of SES explained the insurance-quality associations in the unadjusted models, such as by using a hierarchical modeling approach. Lastly, our primary care measures were operationalized from MEPS rather than the investigator-initiated, which preclude the examination of all the major measures of primary care, especially with regard to measures for the logitudinality and comprehensiveness attributes.

Despite these shortcomings, this study demonstrates important findings to the field and could contribute to improving primary care for diabetic patients. This study reveals equitable primary care quality for diabetes patients despite their health insurance status. In addition to insurance-related differences, other socioeconomic stratification factors, such as the inequality income, education, and occupation, are assumed to be the root cause of disparities in care and population health [21]. Future efforts are needed to investigate both insurance-related and SES-based disparities in healthcare, to identify the major mediators of differences in quality of care. The bulk of the evidence suggests that equitable primary care eliminates racial and ethnic disparities [2225]. Next steps and future directions should be undertaken to examine the role of primary care in improvements in the management of chronic diseases by reducing both insurance and SES-based disparities. In conclusion, the causes of disparities in diabetes care are complex and include societal issues such as lower SES status and poor access to health care. The affordable care act has improved accessibility and affordability of health care. To further improve the quality and equity of primary care for diabetes patients, a number of policy changes could potentially make a positive contribution, such as encouraging new models of care for pre-diabetes and diabetes patients, and raising reimbursement levels for primary care providers who deliver evidence-based diabetes prevention and care.

Conclusions

This study reveals equitable primary care quality for diabetes patients despite their health insurance status. In addition to insurance-related differences, the other socioeconomic stratification factors are assumed to be the root cause of disparities in care. This research emphasizes the crucial role that primary care plays in the accessibility and quality of care for chronically ill patients. Policy makers should continue their commitment to reduce gaps in insurance coverage and improve access as well as quality of diabetic care.

Abbreviations

ACA, Affordable Care Act; ADL, Activities of daily living; AHRQ, Agency for Healthcare Research and Quality; IADL, Instrumental activities of daily living; MEPS, Medical Expenditure Panel Survey; MSA, Metropolitan statistical area; USC, Usual source of care; WHO, World Health Organization

Acknowledgements

Not applicable.

Funding

The study was sponsored by the Johns Hopkins Primary Care Policy Center.

Availability of data and material

The data that support the findings of this study are available from Medical Expenditure Panel Survey, https://meps.ahrq.gov/mepsweb/.

Authors’ contributions

D-CL and LS conceptualized the study; HL provided the analyses; all authors drafted and approved the final manuscript.

Competing interests

The authors declare that they have no competing interests.

Consent for publication

Not applicable.

Ethics approval and consent to participate

Not applicable.

Contributor Information

De-Chih Lee, Phone: 886-4-851-1888, Email: declee@mail.dyu.edu.tw.

Leiyu Shi, Phone: 1-410-614-6507, Email: lshi2@jhu.edu.

References

  • 1.World Health Organization (WHO) Global Health Estimates: Deaths by Cause, Age, Sex and Country, 2000–2012. Geneva: WHO Press; 2014. [Google Scholar]
  • 2.World Health Organization (WHO). Country and Regional Data on Diabetes. http://www.who.int/diabetes/en/. Accessed 21 Mar 2016.
  • 3.Centers for Disease Control and Prevention (CDC) National Diabetes Statistics Report: Estimates of Diabetes and Its Burden in the United States, 2014. Atlanta: U.S. Department of Health and Human Services; 2014. [Google Scholar]
  • 4.Zhang JX, Huang ES, Drum ML, et al. Insurance status and quality of diabetes care in community health centers. Am J Public Health. 2009;99:742–7. doi: 10.2105/AJPH.2007.125534. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 5.Hu R, Shi L, Rane S, et al. Insurance, racial/ethnic, SES-related disparities in quality of care among US adults with diabetes. J Immigr Minor Health. 2014;16:565–75. doi: 10.1007/s10903-013-9966-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6.Booth GL, Bishara P, Lipscombe LL, et al. Universal drug coverage and socioeconomic disparities in major diabetes outcomes. Diabetes Care. 2012;35:2257–64. doi: 10.2337/dc12-0364. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7.Couch C, Sheffield P, Gerthoffer T, et al. Clinical outcomes in patients with type 2 diabetes managed by a diabetes resource nurse in a primary care practice. Proc (Bayl Univ Med Cent) 2003;16:336–40. doi: 10.1080/08998280.2003.11927921. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Morrison F, Shubina M, Goldberg SI, et al. Performance of primary care physicians and other providers on key process measures in the treatment of diabetes. Diabetes Care. 2013;36:1147–52. doi: 10.2337/dc12-1382. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 9.Renders CM, Valk GD, Griffin SJ, et al. Interventions to improve the management of diabetes in primary care, outpatient, and community settings: a systematic review. Diabetes Care. 2001;24:1821–33. doi: 10.2337/diacare.24.10.1821. [DOI] [PubMed] [Google Scholar]
  • 10.Starfield B. Primary Care: Concept, Evaluation, and Policy. New York: Oxford University Press; 1992. [Google Scholar]
  • 11.Shi L, Starfield B, Xu J. Validating the adult primary care assessment tool. J Fam Pract. 2001;50(2):161–75. [Google Scholar]
  • 12.Agency for Healthcare Research and Quality (AHRQ). Medical Expenditure Panel Survey (MEPS). http://meps.ahrq.gov/mepsweb/. 2016. Accessed 21 Mar 2016.
  • 13.Starfield B. Primary Care, Health Services, and Health. New York: Oxford University Press; 1998. [Google Scholar]
  • 14.Shi L. Type of health insurance and the quality of primary care experience. Am J Public Health. 2000;90:1848–55. doi: 10.2105/AJPH.90.12.1848. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Ayanian JZ, Weissman JS, Schneider EC, et al. Unmet health needs of uninsured adults in the United States. JAMA. 2000;284:2061–9. doi: 10.1001/jama.284.16.2061. [DOI] [PubMed] [Google Scholar]
  • 16.Pleis JR, Lethbridge-Cejku M. Summary health statistics for U.S. adults: National Health Interview Survey, 2005. Vital Health Stat. 2006;10:1–153. [PubMed] [Google Scholar]
  • 17.Wilper AP, Woolhandler S, Lasser KE, et al. Health insurance and mortality in US adults. Am J Public Health. 2009;99:2289–95. doi: 10.2105/AJPH.2008.157685. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 18.Abrams M, Nuzum R, Mika S, et al. How the Affordable Care Act will strengthen primary care and benefit patients, providers, and payers. Issue Brief (Commonw Fund) 2011;1:1–28. [PubMed] [Google Scholar]
  • 19.Department of Health and Human Services. Health Insurance Marketplace 2015 Open Enrollment Period: December Enrollment Report, For the Period: November 15, 2014–December 15, 2014. http://aspe.hhs.gov/health/reports/2014/MarketPlaceEnrollment/Dec2014/ib_2014Dec_enrollment.pdf. 2014a. Accessed 21 Mar 2016
  • 20.Department of Health and Human Services. Medicaid and CHIP: October 2014 Monthly Applications, Eligibility Determinations and Enrollment Report, CMS Report. http://www.medicaid.gov/medicaid-chip-program-information/program-information/downloads/october-2014-enrollment-report.pdf. 2014b. Accessed 21 Mar 2016.
  • 21.Adler NE, Newman K. Socioeconomic disparities in health: pathways and policies. Health Aff (Millwood) 2002;21:60–76. doi: 10.1377/hlthaff.21.2.60. [DOI] [PubMed] [Google Scholar]
  • 22.Shi L, Macinko J, Starfield B, et al. The relationship between primary care, income inequality, and mortality in US States, 1980–1995. J Am Board Fam Pract. 2003;16:412–22. doi: 10.3122/jabfm.16.5.412. [DOI] [PubMed] [Google Scholar]
  • 23.Starfield B, Shi L, Macinko J. Contribution of primary care to health systems and health. The Milbank Quarterly. 2005;83(3):457–502. doi: 10.1111/j.1468-0009.2005.00409.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 24.Shi L. The impact of primary care: a focused review. Scientifica (Cairo). \2012;432892. [DOI] [PMC free article] [PubMed]
  • 25.Hayes SL, Riley P, Radley DC, et al. Closing the Gap: past performance of health insurance in reducing racial and ethnic disparities in access to care could Be an indication of future results. Issue Brief (Commonw Fund) 2015;5:1–11. [PubMed] [Google Scholar]

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