RESEARCH
Effect of Massachusetts healthcare reform on racial and ethnic disparities in admissions to hospital for am bulatory care sensitive conditions: retrospective analysis of hospital episode statistics Danny McCormick , 1 Amresh D Hanchate , 23 Karen E Lasser, 3 Meredith G Manze, 3 Mengyun Lin, 3 Chieh Chu, 3 Nancy R Kressin23
O EDITORIAL by Chin
STUDY QUESTION
O RESEARCH, p l l
What impact did the 2006 expansion of health insurance
’ Harvard Medical School, Department of Medicine, Cambridge Health Alliance, Cambridge, MA 02139, USA Veterans Affairs Boston Healthcare System, Boston, MA 02130, USA ’ Section of General Internal Medicine, Boston University School of Medicine, Boston, M A 02118, USA Correspondence to: D McCormick danny_mccormick@
after implementation of reform (July 2006 to December 2007) and multivariate regression to adjust for demograph ics, economic conditions, secular trends, and geographic factors.
coverage in the state of Massachusetts have on rates of preventable admissions to hospital—those that can be prevented with good access to outpatient medical careoverall and according to race and ethnicity?
Primary outcomes, risks, and exposures
SUMMARY ANSWER
The primary outcomes were admission rates for a com posite of 12 ACSCs, overall and by race and ethnicity. The primary exposure was the Massachusetts reform.
The insurance expansion was not associated with changes in rates of preventable admissions overall or with changes in racial and ethnic disparities in this outcome that existed before the reform.
Main results and the role of chance
After adjustment for potential confounders including age, race and ethnicity, sex, county income, unemploy ment rate, and physician supply, we found no evidence of a change in the overall ACSC admission rate (1.2%, 95% confidence interval -1.6% to 4.1%) or of disparities in such rates. The adjusted estimated percentage change in racial/ethnic disparities in Massachusetts versus controls expresses change after reform in disparities between black and white and Hispanic and white people in rates of ACSC after adjustment for changes in control states. Adjusted difference in differences estimates and 95% confidence intervals obtained from Poisson regression models were adjusted for sex, age, race/ethnicity, county income level, county unemployment rate, quarter, and Health Profes sions Shortage Area designation.
hms.harvard.edu Cite this as: BMJ 2 0 1 5 ;3 5 0 :h l4 8 0
doi: 10.1136/bmj.hl480
WHAT IS KNOWN AND WHAT THIS PAPER ADDS Massachusetts healthcare reform increased the proportion of
Thisisasummaryofa paperthat was published on thebmj.com as BMJ2 01 5;3 50:h 1480
the state’s residents who have health insurance, particularly among racial and ethnic minorities. Previous studies of the effects of reform yielded mixed results but had some
thebmj.com O News: Two CDC reports look at regional, racial, and sex disparities in US health (B /W /2013;347:f4672) O Research: Observational intensity bias associated with illness adjustment
{BMJ 2 01 3 ;3 4 6 :f5 4 9 ) O Editorial: Transformative
methodological limitations. This new study shows that the health reform alone seemed insufficient to improve population-wide preventable admissions or pre-existing racial and ethnic disparities in such admissions. To reduce preventable admissions and disparities in preventable admissions, states such as Massachusetts need to ensure that the types of insurance provided underthe expansion are widely accepted by physicians and limit cost barriers to care such as deductibles and copayment requirements.
learning for health equity
{BMJ 2 0 1 3 ;3 4 6 :fl6 4 3 )
Bias, confounding, and other reasons for caution
As we used observational data, confounding in the form of differential secular trends in preventable admissions to hospital among cases and controls could bias findings. Our data sources did not contain information on outpatient care utilisation of the people in the study.
Participants and setting
Residents of Massachusetts, New Jersey, New York, and Pennsylvania aged 18-64. Design, size, and duration
We used a quasi-experimental difference in differences analysis to identify the change in rates of preventable admissions to hospital, overall and according to race and ethnicity, in Massachusetts after reform compared with states not undergoing reform (controls). Preventable admissions were defined as those for any of 12 conditions that can be prevented with good access to care, referred to as ambulatory care sensitive conditions (ACSCs). We estimated changes in such admission rates using state discharge and census data for 21 months before and
Generalisability to other populations
Findings could be generalisable to residents of US states similar to Massachusetts under the Affordable Care Act, the United States’ national health reform that began full implementation in January of 2014. Study funding/potential competing interests
This research was funded by US National Institutes of Health grant 1U01HL105342-01.
C hanges in p re v e n ta b le rates o f adm issio n to h o s p ita l per 1 0 0 0 0 0 r e s id e n ts /y e a r in M ass a c h u s e tts and con trol sta te s in b efore and a fte r reform acc ording to race and e th n ic ity Overall composite ASCS measures
Control states
Before
After
% change
White
667
647
-3.0
Black
1713
Hispanic
1258
1203
Before
Differences in differences estimates
After
% change
Unadjusted
Adjusted (95% Ci)
Adjusted estimated % change (95% Cl)
716
680
-5.1
2.1
2.1 (-0.8 to 5.0)
Ref
°o
12
Massachusetts
2188
2240
2.4
-0.6
-0.5 (-6.0 to 5.3)
-1 .9 (-8.5 to 5.1)
-4.4
1126
1024
-9.1
4.7
1.6 (-3.9 to 5.5)
2.0 (-7.5 to 12.4)
18 A p r il 2 0 1 5 1th e b m j
Copyright of BMJ: British Medical Journal is the property of BMJ Publishing Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Effect of Massachusetts healthcare reform on racial and ethnic disparities in admissions to hospital for am bulatory care sensitive conditions: retrospective analysis of hospital episode statistics Danny McCormick , 1 Amresh D Hanchate , 23 Karen E Lasser, 3 Meredith G Manze, 3 Mengyun Lin, 3 Chieh Chu, 3 Nancy R Kressin23
O EDITORIAL by Chin
STUDY QUESTION
O RESEARCH, p l l
What impact did the 2006 expansion of health insurance
’ Harvard Medical School, Department of Medicine, Cambridge Health Alliance, Cambridge, MA 02139, USA Veterans Affairs Boston Healthcare System, Boston, MA 02130, USA ’ Section of General Internal Medicine, Boston University School of Medicine, Boston, M A 02118, USA Correspondence to: D McCormick danny_mccormick@
after implementation of reform (July 2006 to December 2007) and multivariate regression to adjust for demograph ics, economic conditions, secular trends, and geographic factors.
coverage in the state of Massachusetts have on rates of preventable admissions to hospital—those that can be prevented with good access to outpatient medical careoverall and according to race and ethnicity?
Primary outcomes, risks, and exposures
SUMMARY ANSWER
The primary outcomes were admission rates for a com posite of 12 ACSCs, overall and by race and ethnicity. The primary exposure was the Massachusetts reform.
The insurance expansion was not associated with changes in rates of preventable admissions overall or with changes in racial and ethnic disparities in this outcome that existed before the reform.
Main results and the role of chance
After adjustment for potential confounders including age, race and ethnicity, sex, county income, unemploy ment rate, and physician supply, we found no evidence of a change in the overall ACSC admission rate (1.2%, 95% confidence interval -1.6% to 4.1%) or of disparities in such rates. The adjusted estimated percentage change in racial/ethnic disparities in Massachusetts versus controls expresses change after reform in disparities between black and white and Hispanic and white people in rates of ACSC after adjustment for changes in control states. Adjusted difference in differences estimates and 95% confidence intervals obtained from Poisson regression models were adjusted for sex, age, race/ethnicity, county income level, county unemployment rate, quarter, and Health Profes sions Shortage Area designation.
hms.harvard.edu Cite this as: BMJ 2 0 1 5 ;3 5 0 :h l4 8 0
doi: 10.1136/bmj.hl480
WHAT IS KNOWN AND WHAT THIS PAPER ADDS Massachusetts healthcare reform increased the proportion of
Thisisasummaryofa paperthat was published on thebmj.com as BMJ2 01 5;3 50:h 1480
the state’s residents who have health insurance, particularly among racial and ethnic minorities. Previous studies of the effects of reform yielded mixed results but had some
thebmj.com O News: Two CDC reports look at regional, racial, and sex disparities in US health (B /W /2013;347:f4672) O Research: Observational intensity bias associated with illness adjustment
{BMJ 2 01 3 ;3 4 6 :f5 4 9 ) O Editorial: Transformative
methodological limitations. This new study shows that the health reform alone seemed insufficient to improve population-wide preventable admissions or pre-existing racial and ethnic disparities in such admissions. To reduce preventable admissions and disparities in preventable admissions, states such as Massachusetts need to ensure that the types of insurance provided underthe expansion are widely accepted by physicians and limit cost barriers to care such as deductibles and copayment requirements.
learning for health equity
{BMJ 2 0 1 3 ;3 4 6 :fl6 4 3 )
Bias, confounding, and other reasons for caution
As we used observational data, confounding in the form of differential secular trends in preventable admissions to hospital among cases and controls could bias findings. Our data sources did not contain information on outpatient care utilisation of the people in the study.
Participants and setting
Residents of Massachusetts, New Jersey, New York, and Pennsylvania aged 18-64. Design, size, and duration
We used a quasi-experimental difference in differences analysis to identify the change in rates of preventable admissions to hospital, overall and according to race and ethnicity, in Massachusetts after reform compared with states not undergoing reform (controls). Preventable admissions were defined as those for any of 12 conditions that can be prevented with good access to care, referred to as ambulatory care sensitive conditions (ACSCs). We estimated changes in such admission rates using state discharge and census data for 21 months before and
Generalisability to other populations
Findings could be generalisable to residents of US states similar to Massachusetts under the Affordable Care Act, the United States’ national health reform that began full implementation in January of 2014. Study funding/potential competing interests
This research was funded by US National Institutes of Health grant 1U01HL105342-01.
C hanges in p re v e n ta b le rates o f adm issio n to h o s p ita l per 1 0 0 0 0 0 r e s id e n ts /y e a r in M ass a c h u s e tts and con trol sta te s in b efore and a fte r reform acc ording to race and e th n ic ity Overall composite ASCS measures
Control states
Before
After
% change
White
667
647
-3.0
Black
1713
Hispanic
1258
1203
Before
Differences in differences estimates
After
% change
Unadjusted
Adjusted (95% Ci)
Adjusted estimated % change (95% Cl)
716
680
-5.1
2.1
2.1 (-0.8 to 5.0)
Ref
°o
12
Massachusetts
2188
2240
2.4
-0.6
-0.5 (-6.0 to 5.3)
-1 .9 (-8.5 to 5.1)
-4.4
1126
1024
-9.1
4.7
1.6 (-3.9 to 5.5)
2.0 (-7.5 to 12.4)
18 A p r il 2 0 1 5 1th e b m j
Copyright of BMJ: British Medical Journal is the property of BMJ Publishing Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
