Both clinical epidemiology and population health perspectives can define the role of health care in reducing health disparities

How effects on health equity are assessed in systematic reviews of interventions

BACKGROUND

Enhancing health equity is endorsed in the Sustainable Development Goals. The failure of systematic reviews to consider potential differences in effects across equity factors is cited by decision-makers as a limitation to their ability to inform policy and program decisions.  OBJECTIVES: To explore what methods systematic reviewers use to consider health equity in systematic reviews of effectiveness.

SEARCH METHODS

We searched the following databases up to 26 February 2021: MEDLINE, PsycINFO, the Cochrane Methodology Register, CINAHL, Education Resources Information Center, Education Abstracts, Criminal Justice Abstracts, Hein Index to Foreign Legal Periodicals, PAIS International, Social Services Abstracts, Sociological Abstracts, Digital Dissertations and the Health Technology Assessment Database. We searched SCOPUS to identify articles that cited any of the included studies on 10 June 10 2021. We contacted authors and searched the reference lists of included studies to identify additional potentially relevant studies.

SELECTION CRITERIA

We included empirical studies of cohorts of systematic reviews that assessed methods for measuring effects on health inequalities. We define health inequalities as unfair and avoidable differences across socially stratifying factors that limit opportunities for health. We operationalised this by assessing studies which evaluated differences in health across any component of the PROGRESS-Plus acronym, which stands for Place of residence, Race/ethnicity/culture/language, Occupation, Gender or sex, Religion, Education, Socioeconomic status, Social capital. "Plus" stands for other factors associated with discrimination, exclusion, marginalisation or vulnerability such as personal characteristics (e.g. age, disability), relationships that limit opportunities for health (e.g. children in a household with parents who smoke) or environmental situations which provide limited control of opportunities for health (e.g. school food environment).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data using a pre-tested form. Risk of bias was appraised for included studies according to the potential for bias in selection and detection of systematic reviews.  MAIN RESULTS: In total, 48,814 studies were identified and the titles and abstracts were screened in duplicate. In this updated review, we identified an additional 124 methodological studies published in the 10 years since the first version of this review, which included 34 studies. Thus, 158 methodological studies met our criteria for inclusion. The methods used by these studies focused on evidence relevant to populations experiencing health inequity (108 out of 158 studies), assess subgroup analysis across PROGRESS-Plus (26 out of 158 studies), assess analysis of a gradient in effect across PROGRESS-Plus (2 out of 158 studies) or use a combination of subgroup analysis and focused approaches (20 out of 158 studies). The most common PROGRESS-Plus factors assessed were age (43 studies), socioeconomic status in 35 studies, low- and middle-income countries in 24 studies, gender or sex in 22 studies, race or ethnicity in 17 studies, and four studies assessed multiple factors across which health inequity may exist. Only 16 studies provided a definition of health inequity. Five methodological approaches to consider health equity in systematic reviews of effectiveness were identified: 1) descriptive assessment of reporting and analysis in systematic reviews (140 of 158 studies used a type of descriptive method); 2) descriptive assessment of reporting and analysis in original trials (50 studies); 3) analytic approaches which assessed differential effects across one or more PROGRESS-Plus factors (16 studies); 4) applicability assessment (25 studies) and 5) stakeholder engagement (28 studies), which is a new finding in this update and examines the appraisal of whether relevant stakeholders with lived experience of health inequity were included in the design of systematic reviews or design and delivery of interventions. Reporting for both approaches (analytic and applicability) lacked transparency and was insufficiently detailed to enable the assessment of credibility.

AUTHORS' CONCLUSIONS

There is a need for improvement in conceptual clarity about the definition of health equity, describing sufficient detail about analytic approaches (including subgroup analyses) and transparent reporting of judgments required for applicability assessments in order to consider health equity in systematic reviews of effectiveness.

Ethnic differences in body composition, sociodemographic characteristics and lifestyle in people with type 2 diabetes mellitus living in Italy

This study aimed to compare immigrants and Italian natives with type 2 diabetes mellitus (DM2) in terms of anthropometric parameters and lifestyle-related characteristics and to investigate the relationship between ethnicity and glycemic control in men and women with DM2 living in Italy. The sample included 100 immigrants (55 Albanians and 45 Africans) and 100 Italians, followed by the Public Health Clinics of Rimini. The association of ethnicity with sex, socioeconomic status, anthropometric and hematological characteristics, and lifestyle were examined. In addition, differences among groups in glycemic control were evaluated. Among males, African participants presented significantly lower values than other groups in adiposity parameters and triglycerides. The highest percentage of obesity and of normal weight was found in Italians and in Africans, respectively. Among females, there were scanty differences, but Italians presented higher WHR values than the other groups. No statistical differences appeared in hematological parameters among groups. There were no significant differences in glycemic control among groups and sexes. Also considering the differences between subjects with optimal (L) or nonoptimal (H) glycemic control, the differences in lifestyle, anthropometric, and hematological variables remained scarce. Among all groups, significantly higher values of glucose were detected in H than in L. A similar condition appeared for triglycerides in males. Immigrant and native Italian diabetics did not present any difference in their clinical characteristics, but Italians generally presented worst lifestyle habits. The percentage of subjects with poor metabolic control of diabetes was not low, but similar in immigrants and natives.

When is a randomised controlled trial health equity relevant? Development and validation of a conceptual framework

BACKGROUND

Randomised controlled trials can provide evidence relevant to assessing the equity impact of an intervention, but such information is often poorly reported. We describe a conceptual framework to identify health equity-relevant randomised trials with the aim of improving the design and reporting of such trials.

METHODS

An interdisciplinary and international research team engaged in an iterative consensus building process to develop and refine the conceptual framework via face-to-face meetings, teleconferences and email correspondence, including findings from a validation exercise whereby two independent reviewers used the emerging framework to classify a sample of randomised trials.

RESULTS

A randomised trial can usefully be classified as 'health equity relevant' if it assesses the effects of an intervention on the health or its determinants of either individuals or a population who experience ill health due to disadvantage defined across one or more social determinants of health. Health equity-relevant randomised trials can either exclusively focus on a single population or collect data potentially useful for assessing differential effects of the intervention across multiple populations experiencing different levels or types of social disadvantage. Trials that are not classified as 'health equity relevant' may nevertheless provide information that is indirectly relevant to assessing equity impact, including information about individual level variation unrelated to social disadvantage and potentially useful in secondary modelling studies.

CONCLUSION

The conceptual framework may be used to design and report randomised trials. The framework could also be used for other study designs to contribute to the evidence base for improved health equity.

Focus on migrants with type 2 diabetes mellitus in European Countries

The prevalence of type 2 diabetes mellitus, one of the major causes of morbility and mortality in Europe, is increasing in all European countries. Diabetes is not distributed equally among all population groups, as higher incidence, appearance of complications, and different mortality rates have been observed among migrants and the native population. These differences may be due to genetic profiles, lifestyle, and utilization of the health care system in different ways. Taking into account that the quantity of migrants is nowadays increasing, mainly in the southern part of Europe, the knowledge of diabetes in migrants through a better collection of data is necessary, considering that few limited epidemiological studies have evaluated the importance of this problem in EU countries. A special effort in developing a comprehensive management for native and immigrant populations in order to prevent and cure diabetes should be mandatory. This activity could be helpful to limit the incidence of future diabetes complications and to avoid the consequent burden of the health care system along with a control on its costs. It is clear that diabetes complication prevention is essential for long-term sustainability of the health care system.

Absence of a Socioeconomic Gradient in Older Adults' Survival with Multiple Chronic Conditions

BACKGROUND

Individuals of low socioeconomic status experience a disproportionate burden of chronic conditions; however it is unclear whether chronic condition burden affects survival differently across socioeconomic strata.

METHODS

This retrospective cohort study used health administrative data from all residents of Ontario, Canada aged 65 to 105 with at least one of 16 chronic conditions on April 1, 2009 (n = 1,518,939). Chronic condition burden and unadjusted mortality were compared across neighborhood income quintiles. Multivariable Cox proportional hazards models were used to examine the effect of number of chronic conditions on two-year survival across income quintiles.

FINDINGS

Prevalence of five or more chronic conditions was significantly higher among older adults in the poorest neighborhoods (18.2%) than the wealthiest (14.3%) (Standardized difference > 0·1). There was also a socioeconomic gradient in unadjusted mortality over two years: 10.1% of people in the poorest neighborhoods died compared with 7.6% of people in the wealthiest neighborhoods. In adjusted analyses, having more chronic conditions was associated with a statistically significant increase in hazard of death over two years, however the magnitude of this effect was comparable across income quintiles. Individuals in the poorest neighborhoods with four chronic conditions had 2.07 times higher hazard of death (95% CI: 1.97-2.19) than those with one chronic condition, but this was comparable to the hazard associated with four chronic conditions in the wealthiest neighborhoods (HR: 2.29, 95% CI: 2.16-2.43).

INTERPRETATION

Among older adults with universal access to health care, the deleterious effect of increasing chronic condition burden on two-year hazard of death was consistent across neighborhood income quintiles once baseline differences in condition burden were accounted for. This may be partly attributable to equal access to, and utilization of, health care. Alternate explanations for these findings, including study limitations, are also discussed.

Cardiovascular health in migrants: current status and issues for prevention. A collaborative multidisciplinary task force report

OBJECTIVES

To review information on cardiovascular health and migration, to stress the attention of researchers that much needs to be done in the collection of sound data in Italy and to allow policy makers identifying this issue as an important public health concern.

BACKGROUND

In Italy, the rate of immigrants in the total number of residents increased from 2.5% in 1990 to 7.4% in 2010, and currently exceeds 10% in regions such as Lombardia, Emilia Romagna and Toscana.

METHODS

A consensus statement was developed by approaching relevant Italian national scientific societies involved in cardiovascular prevention. Task force members were identified by the president and/or the boards of each relevant scientific society or working group, as appropriate. To obtain a widespread consensus, drafts were merged and distributed to the scientific societies for local evaluation and revision by as many experts as possible. The ensuing final draft was finally approved by scientific societies.

RESULTS

In several western European countries, the prevalence of hypertension, diabetes, chronic kidney disease, obesity and metabolic syndrome was found to be higher among immigrants than in the native population. Although migrants are often initially healthier than non-migrant populations in their host countries, genetic factors, and changing environments with lifestyle changes, social exclusion and insufficient medical control may expose them to health challenges. Cultural reasons may also hamper both the dissemination of prevention strategies and migrant communication with healthcare providers. However, great diversity exists across and within different groups of migrants, making generalizations very difficult and many countries do not collect registry or survey data for migrant's health.

CONCLUSIONS

In the present economic context, the European Union is placing great attention to improve data collection for migrant health and to support the implementation of specific prevention policies aimed at limiting the future burden of cardiovascular and renal disease, and the consequent load for health systems. Wider initiatives on the topic are awaited in Italy.

Neighborhood income and stroke care and outcomes

OBJECTIVE

To evaluate factors that may contribute to the increased stroke case fatality rates observed in individuals from low-income areas.

METHODS

We conducted a cohort study on a population-based sample of all patients with stroke or TIA seen at 153 acute care hospitals in the province of Ontario, Canada, between April 1, 2002, and March 31, 2003, and April 1, 2004, and March 31, 2005. Socioeconomic status measured as income quintiles was imputed from median neighborhood income. In the study sample of 7,816 patients we determined 1-year mortality by grouped income quintile and used multivariable analyses to assess whether differences in survival were explained by cardiovascular risk factors, stroke severity, stroke management, or other prognostic factors.

RESULTS

There was no significant gradient across income groups for stroke severity or stroke management. However, 1-year mortality rates were higher in those from the lowest income group compared to those from the highest income group, even after adjustment for age, sex, stroke type and severity, comorbid conditions, hospital and physician characteristics, and processes of care (adjusted hazard ratio for low- vs high-income groups, 1.18; 95 confidence interval 1.03 to 1.29).

CONCLUSIONS

In Ontario, 1-year survival rates after an index stroke are higher for those from the richest compared to the least wealthy areas, and this is only partly explained by age, sex, comorbid conditions, and other baseline risk factors.

Predictive risk algorithms in a population setting: an overview

BACKGROUND

The widespread use of risk algorithms in clinical medicine is testimony to how they have helped transform clinical decision-making. Risk algorithms have a similar but underdeveloped potential to support decision-making for population health.

OBJECTIVE

To describe the role of predictive risk algorithms in a population setting.

METHODS

First, predictive risk algorithms and how clinicians use them are described. Second, the population uses of risk algorithms are described, highlighting the strengths of risk algorithms for health planning. Lastly, the way in which predictive risk algorithms are developed is discussed briefly and a guide for algorithm assessment in population health presented.

CONCLUSION

For the past 20 years, absolute and baseline risk has been a cornerstone of population health planning. The most accurate and discriminating method to generate such estimates is the use of multivariable risk algorithms. Routinely collected data can be used to develop algorithms with characteristics that are well suited to health planning and such data are increasingly available. The widespread use of risk algorithms in clinical medicine is testimony to how they have helped transform clinical decision-making. Risk algorithms have a similar but underdeveloped potential to support decision-making for population health.

Socioeconomic equity in amenable mortality in Finland 1992-2008

This study presents an approach to assess socioeconomic equity in the effectiveness of health services. As an indicator of health system performance we use amenable mortality which captures premature deaths that should not occur in the presence of effective and timely health care. Data on amenable deaths by income groups in Finland in 1992-2008 came from the National Causes of Death Register which was linked to sociodemographic data in population registers. We evaluate the extent of and trends in socioeconomic differences with two widely used inequity indices, the concentration index and the slope index of inequality, and also for different categories of amenable mortality. By categorizing conditions according to the level of intervention associated with the conditions it is possible to evaluate the effect of types of health interventions. Causes of death attributable to specialized and primary care interventions comprise the main groups. By this approach of decomposing equity in amenable mortality in Finland we detected major and increasing socioeconomic inequities and also greater inequity among deaths amenable to specialized health care interventions. Moreover, we saw that inequity increased at a faster pace among deaths amenable to specialized health care interventions yet primary health care interventions made a greater contribution to overall inequity. Although the overall rate of amenable mortality decreased notably during the follow-up, the time trends of socioeconomic differences in amenable health care indicate a substantial increase in inequities in health care in Finland.

Avoidable mortality for causes amenable to medical care, by occupation in Canada, 1991-2001

OBJECTIVE

To describe the incidence of avoidable mortality for causes amenable to medical care among occupation groups in Canada.

METHOD

A cohort study over an 11-year period among a representative 15% sample of the non-institutionalized population of Canada aged 30-69 at cohort inception. Age-standardized mortality rates for causes amenable to medical care and all other causes of death were calculated for occupationally-active men and women in five categories of skill level and 80 specific occupational groups as well as for persons not occupationally active.

RESULTS

Age-standardized mortality rates per 100,000 person-years at risk for causes amenable to medical care and for all other causes were 132.3 and 218.6, respectively, for occupationally-active women, and 216.6 and 449.3 for occupationally-active men. For causes amenable to medical care and for all other causes, for both sexes, there was a gradient in mortality relative to the five-level ranking by occupational skill level, but the gradient was less strong for women than for men. Across the 80 occupation minor groups, for both men and women, there was a linear relationship between the rates for causes amenable to medical care and the rates for all other causes.

CONCLUSIONS

For occupationally-active adults, this study found similar gradients in mortality for causes amenable to medical care and for all other causes of mortality over the period 1991-2001. Avoidable mortality is a valuable indicator of population health, providing information on outcomes pertinent to the organization and delivery of health care services.

How effects on health equity are assessed in systematic reviews of interventions

BACKGROUND

Enhancing health equity has now achieved international political importance with endorsement from the World Health Assembly in 2009.  The failure of systematic reviews to consider effects on health equity is cited by decision-makers as a limitation to their ability to inform policy and program decisions. 

OBJECTIVES

To systematically review methods to assess effects on health equity in systematic reviews of effectiveness.

SEARCH STRATEGY

We searched the following databases up to July 2 2010: MEDLINE, PsychINFO, the Cochrane Methodology Register, CINAHL, Education Resources Information Center, Education Abstracts, Criminal Justice Abstracts, Index to Legal Periodicals, PAIS International, Social Services Abstracts, Sociological Abstracts, Digital Dissertations and the Health Technology Assessment Database. We searched SCOPUS to identify articles that cited any of the included studies on October 7 2010.

SELECTION CRITERIA

We included empirical studies of cohorts of systematic reviews that assessed methods for measuring effects on health inequalities.

DATA COLLECTION AND ANALYSIS

Data were extracted using a pre-tested form by two independent reviewers. Risk of bias was appraised for included studies according to the potential for bias in selection and detection of systematic reviews. 

MAIN RESULTS

Thirty-four methodological studies were included.  The methods used by these included studies were: 1) Targeted approaches (n=22); 2) gap approaches (n=12) and gradient approach (n=1).  Gender or sex was assessed in eight out of 34 studies, socioeconomic status in ten studies, race/ethnicity in seven studies, age in seven studies, low and middle income countries in 14 studies, and two studies assessed multiple factors across health inequity may exist.Only three studies provided a definition of health equity. Four methodological approaches to assessing effects on health equity were identified: 1) descriptive assessment of reporting and analysis in systematic reviews (all 34 studies used a type of descriptive method); 2) descriptive assessment of reporting and analysis in original trials (12/34 studies); 3) analytic approaches (10/34 studies); and 4) applicability assessment (11/34 studies). Both analytic and applicability approaches were not reported transparently nor in sufficient detail to judge their credibility.

AUTHORS' CONCLUSIONS

There is a need for improvement in conceptual clarity about the definition of health equity, describing sufficient detail about analytic approaches (including subgroup analyses) and transparent reporting of judgments required for applicability assessments in order to assess and report effects on health equity in systematic reviews.

Inequities in screening for sexually transmitted infections in African American adolescents: can health policy help?

Although rates of sexually transmitted infections (STIs) in African Americans are higher than other populations, there are disparities in the screening and treatment of STIs for African American adolescents. Many African Americans distrust the health care system, resulting in a reluctance to seek health care. Adolescents may lack access to and the resources to pay for health care. This article reviews historical events believed to influence African American distrust of the health care system, discusses socioeconomic factors influencing adolescent access to services, and offers descriptions of services available to assist adolescents in receiving preventative services. Last, potential health policy solutions for nurses are noted.

Assessing equity in clinical practice guidelines

Recognition of the need for systematically developed clinical practice guidelines (CPGs) has increased dramatically over the past 20 years. CPGs have focused primarily on the effectiveness of interventions, explicitly or implicitly addressing the following question: Will adherence to a recommendation do more good than harm? At times they have also focused on the cost-effectiveness of interventions: Are the net benefits worth the costs? They rarely have focused on equity: Are the recommendations fair? The Knowledge Plus Project of the International Clinical Epidemiology Network attempts to improve the process of CPG development by formulating strategies to consider not just technical issues (effectiveness, and efficiency) but sociopolitical dimensions as well (equity and local appropriateness). This article discusses a proposed lens for users to evaluate how well CPGs address issues of equity.

Avoidable mortality by neighbourhood income in Canada: 25 years after the establishment of universal health insurance

AIM

To examine neighbourhood income differences in deaths amenable to medical care and public health over a 25-year period after the establishment of universal insurance for doctors and hospital services in Canada.

METHODS

Data for census metropolitan areas were obtained from the Canadian Mortality Database and population censuses for the years 1971, 1986, 1991 and 1996. Deaths amenable to medical care, amenable to public health, from ischaemic heart disease and from other causes were considered. Data on deaths were grouped into neighbourhood income quintiles on the basis of the census tract percentage of population below Canada's low-income cut-offs.

RESULTS

From 1971 to 1996, differences between the richest and poorest quintiles in age-standardised expected years of life lost amenable to medical care decreased 60% (p<0.001) in men and 78% (p<0.001) in women, those amenable to public health increased 0.7% (p = 0.94) in men and 20% (p = 0.55) in women, those lost from ischaemic heart disease decreased 58% in men and 38% in women, and from other causes decreased 15% in men and 9% in women. Changes in the age-standardised expected years of life lost difference for deaths amenable to medical care were significantly larger than those for deaths amenable to public health or other causes for both men and women (p<0.001).

CONCLUSIONS

Reductions in rates of deaths amenable to medical care made the largest contribution to narrowing socioeconomic mortality disparities. Continuing disparities in mortality from causes amenable to public health suggest that public health initiatives have a potentially important, but yet un-realized, role in further reducing mortality disparities in Canada.

Disparities in stroke preventive care in general practice did not explain socioeconomic disparities in stroke

OBJECTIVE

To assess socioeconomic disparities in stroke incidence and in the quality of preventive care for stroke in the Netherlands.

STUDY DESIGN AND SETTINGS

A total of 190,664 patients who registered in 96 general practices were followed up for 12 months. Data were collected on diagnoses, referrals, prescriptions, and diagnostic procedures. Hazard ratios (HR) were calculated to assess the association between educational level and stroke incidence. Multilevel logistic regression was used to assess socioeconomic disparities in the quality of preventive care for stroke precursors.

RESULTS

Lower educational level was associated with higher incidence of stroke in men (HR=1.36, 95% CI=1.06-1.74) but not in women. Among both men and women, there were socioeconomic disparities in the prevalence of hypertension, hypercholesterolemia, diabetes, angina pectoris, heart failure, and peripheral artery disease. Lower educated hypercholesterolemia patients under medication were less likely to be prescribed statins (odds ratio=0.62, 95% CI=0.42-0.91). However, for other precursors of stroke, there were no major disparities in the quality of preventive care.

CONCLUSION

There are socioeconomic disparities in stroke incidence among men but not among women. Socioeconomic differences in factors such as hypertension and diabetes are likely to contribute to stroke disparities. However, general practitioners (GPs) provide care of a similar quality to patients from different socioeconomic groups.

The basic principles of migration health: population mobility and gaps in disease prevalence

Currently, migrants and other mobile individuals, such as migrant workers and asylum seekers, are an expanding global population of growing social, demographic and political importance. Disparities often exist between a migrant population's place of origin and its destination, particularly with relation to health determinants. The effects of those disparities can be observed at both individual and population levels. Migration across health and disease disparities influences the epidemiology of certain diseases globally and in nations receiving migrants. While specific disease-based outcomes may vary between migrant group and location, general epidemiological principles may be applied to any situation where numbers of individuals move between differences in disease prevalence. Traditionally, migration health activities have been designed for national application and lack an integrated international perspective. Present and future health challenges related to migration may be more effectively addressed through collaborative global undertakings. This paper reviews the epidemiological relationships resulting from health disparities bridged by migration and describes the growing role of migration and population mobility in global disease epidemiology. The implications for national and international health policy and program planning are presented.