Directly observed therapy for tuberculosis: the Harlem Hospital experience, 1993

Introduction of short course treatment for latent tuberculosis infection at a primary care facility for refugees in Winnipeg, Canada: A mixed methods evaluation

Background

The World Health Organization (WHO) End TB strategy document 'Toward tuberculosis elimination: an action framework for low incidence countries'-like Canada- identifies screening and treatment of latent tuberculosis infection (LTBI) for groups at increased risk for TB disease as a priority, including newcomers from endemic countries. In 2015, the clients-centered model offered at a primary care facility for refugees, BridgeCare Clinic, Winnipeg, Canada was evaluated. The model included LTBI screening, assessment, and treatment, and originally offered 9-months of isoniazid as treatment. This mixed methods evaluation investigates LTBI program outcomes since the introduction of two short-course treatment regimens: 4-months of rifampin, and 3-months of isoniazid and rifapentine.

Methods

This study combined a retrospective analysis of program administrative data with structured interviews of clinic staff. We included LTBI treatment eligibility, the treatment regimen offered, treatment initiation, and completed treatment from January 1, 2015 to August 6, 2020.

Results

Seven hundred and one people were screened, and infection rates varied from 34.1% in 2015 to 53.3% in 2020. Most people living with LTBI came from high TB burden countries in Africa and South-East Asia WHO regions and were younger than 45 years old. Treatment eligibility increased 9% (75% in 2015 to 86% in 2016-2020) and most people diagnosed with LTBI took the short course treatments offered. There was an increase of 14.5% in treatment initiation (75.6 vs. 90.1%), and an increase of 8% in treatment completion (82.4 vs. 90.4%) after short-course regimens were introduced. The final model showed that the treatment regimen tends to affect the frequency of treatment completion, but there are other factors that influence this outcome, in this population. With the new treatments, BridgeCare Clinic achieved the 90% of treatment coverage, and the 90% treatment completion rate targets recommended in the End TB Strategy. Qualitative interviews with clinic staff further affirm the higher acceptability of the new treatments.

Conclusion

While these results are limited to government-sponsored refugees in Winnipeg, they highlight the acceptability and value of short-course LTBI treatment as a possibility for reaching End TB targets in primary care settings.

Integrated Care for Latent Tuberculosis Infection (LTBI) at a Primary Health Care Facility for Refugees in Winnipeg, Canada: A Mixed-Methods Evaluation

Although Canada has one of the lowest tuberculosis incidence rates in the world, certain groups are disproportionately affected, including foreign born people from high incidence countries. The Winnipeg Regional Health Authority has initiated a process to decentralize latent tuberculosis infection (LTBI) management at primary care clinics in Winnipeg. One of these clinics is BridgeCare Clinic which provides services to government-assisted refugees. The present study describes the BridgeCare Clinic LTBI program and reviews program outcomes from January 2015 to October 2016. Refugees at BridgeCare Clinic receive comprehensive care, including LTBI screening and treatment. The LTBI program is managed by physicians, nurse practitioners, and primary care nurses under a patient-centered model of care. An accessible interpretation service, education to clients, and laboratory sampling at the clinic with free IGRA testing are important components of the program. Anonymized data on client outcomes were statistically analyzed and qualitative interviews were conducted with senior staff. During the study period, 274 IGRA tests were ordered with 158 negative results (57.7%) and 101 positive results (36.9%). Of 45 clients eligible (from January to December 2015) for LTBI treatment, 11 (24.4%) declined to receive treatment and 34 (75.6%) started treatment. Twenty-seven (79.4%) clients completed treatment, 3 (8.8%) clients moved out of province, and 4 (11.8%) did not complete treatment. The most recent World Health Organization strategy for tuberculosis control calls for integrated, patient-centered care and prevention. Aligned with these WHO recommendations, our experience suggests that LTBI care and treatment can be delivered effectively in a primary care setting using an integrated patient-centered approach.

Effects of a multicomponent intervention to streamline initiation of antiretroviral therapy in Africa: a stepped-wedge cluster-randomised trial

BACKGROUND

In Africa, up to 30% of HIV-infected patients who are clinically eligible for antiretroviral therapy (ART) do not start timely treatment. We assessed the effects of an intervention targeting prevalent health systems barriers to ART initiation on timing and completeness of treatment initiation.

METHODS

In this stepped-wedge, non-blinded, cluster-randomised controlled trial, 20 clinics in southwestern Uganda were randomly assigned in groups of five clinics every 6 months to the intervention by a computerised random number generator. This procedure continued until all clinics had crossed over from control (standard of care) to the intervention, which consisted of opinion-leader-led training and coaching of front-line health workers, a point-of-care CD4 cell count testing platform, a revised counselling approach without mandatory multiple pre-initiation sessions, and feedback to the facilities on their ART initiation rates and how they compared with other facilities. Treatment-naive, HIV-infected adults (aged ≥18 years) who were clinically eligible for ART during the study period were included in the study population. The primary outcome was ART initiation 14 days after first clinical eligibility for ART. This study is registered with ClinicalTrials.gov, number NCT01810289.

FINDINGS

Between April 11, 2013, and Feb 2, 2015, 12 024 eligible patients visited one of the 20 participating clinics. Median CD4 count was 310 cells per μL (IQR 179-424). 3753 of 4747 patients (weighted proportion 80%) in the intervention group had started ART by 2 weeks after eligibility compared with 2585 of 7066 patients (38%) in the control group (risk difference 41·9%, 95% CI 40·1-43·8). Vital status was ascertained in a random sample of 208 patients in the intervention group and 199 patients in the control group. Four deaths (2%) occurred in the intervention group and five (3%) occurred in the control group.

INTERPRETATION

A multicomponent intervention targeting health-care worker behaviour increased the probability of ART initiation 14 days after eligibility. This intervention consists of widely accessible components and has been tested in a real-world setting, and is therefore well positioned for use at scale.

FUNDING

National Institute of Allergy and Infectious Diseases (NIAID) and the President's Emergency Fund for AIDS Relief (PEPFAR).

Outcome of a grocery voucher incentive scheme for low-income tuberculosis patients on directly observed therapy in Singapore

INTRODUCTION

The 'DOT & Shop' scheme is sponsored by SATA CommHealth, a local non-governmental organisation. It was launched in July 2009, in collaboration with Singapore's Tuberculosis Control Unit (TBCU). Under this scheme, grocery vouchers are disbursed to low-income patients with tuberculosis (TB) at each clinic visit if they have been adherent to directly observed therapy (DOT). This study aimed to determine the effect of this incentive scheme on treatment completion rates and to report the characteristics of patients who were non-adherent to the scheme.

METHODS

This descriptive study used data from the TBCU medical social worker database and the National TB Registry.

RESULTS

From July 2009 to December 2012, a total of 883 TB patients were enrolled in the scheme. The overall treatment completion rates of the patients before (July 2006-June 2009) and after (July 2009-December 2012) the implementation of the scheme improved from 85.3% to 87.2% (p = 0.02). Patients under this scheme had a higher treatment completion rate (90.0%) than those not under this scheme (86.4%) (p < 0.01). It was found that the non-adherent patients were more likely to be of Malay ethnicity, younger and unemployed.

CONCLUSION

We demonstrate the salutary effect of a non-governmental organisation-funded grocery voucher incentive scheme for low-income TB patients on DOT in Singapore.

Enhanced tuberculosis case detection among substitution treatment patients: a randomized controlled trial

Background

Historically, HIV, TB (tuberculosis) and illegal drug treatment services in Estonia have been developed as vertical structures. Related health care services are often provided by different health care institutions and in different locations. This may present obstacles for vulnerable groups, such as injecting drug users (IDU), to access the needed services. We conducted a small scale randomized controlled trial to evaluate a case management intervention aimed at increasing TB screening and treatment entry among IDUs referred from a methadone drug treatment program in Jõhvi, North-Eastern Estonia.

Findings

Of the 189 potential subjects, 112 (59%) participated. HIV prevalence was 86% (n = 96) and 7.4% (n = 8) of participants were interferon gamma release assay (IGRA) positive (6.5% were both HIV and IGRA-positive, n = 7). Overall, 44% of participants (n = 49) attended TB clinic, 17 (30%) from control group and 32 (57%) from case management group (p = 0.004). None of the participants were diagnosed with TB. In a multivariate model, those randomized to case management group were more likely to access TB screening services.

Conclusions

These findings demonstrate the urgent need for scaling up TB screening among IDUs and the value of more active approach in referring substitution treatment patients to TB services.

Trial registration

ClinicalTrials.gov: NCT01290081

Mycobacterium tuberculosis: implications for district nurses

Despite the belief of many health professionals, tuberculosis is not a disease of the past but is on the increase (Department of Health (DH), 2004) and the UK has seen a year on year increase in the number of new cases (Health Protection Agency, 2008). The DH have made a number of recommendations to combat this increase and one of those recommendations is to raise awareness among health staff (2004). This review has set out to examine district nurses' knowledge about tuberculosis and the consequences of poor knowledge. Five themes emerged from the literature search with the most prominent being the subject of adherence and how this could be addressed. The review has identified that district nurses should have a greater knowledge of tuberculosis and patient treatment could be improved by the nurse having a better understanding about tuberculosis care.

Tuberculosis and illicit drug use: review and update

Illicit drug users continue to be a group at high risk for tuberculosis (TB). Here, we present an updated review of the relationship between TB and illicit drug use, and we summarize more than a decade of new research. Drug users, and injection drug users in particular, have driven TB epidemics in a number of countries. The successful identification and treatment of TB among illicit drug users remain important components of a comprehensive TB strategy, but illicit drug users present a unique set of challenges for TB diagnosis and control. New diagnostic modalities, including interferon-gamma-release assays, offer potential for improved diagnosis and surveillance among this group, along with proven treatment strategies that incorporate the use of directly observed therapy with treatment for drug abuse. Special considerations, including coinfection with viral hepatitis and the rifampin-methadone drug interaction, warrant clinical attention and are also updated here.

[Measurement in public health: what pulmonary tuberculosis management has taught us]

Pulmonary tuberculosis rates are increasing worldwide, including in Spain. One of the main challenges when treating this disease is achieving treatment completion, since studies have shown that approximately 30-35% of all patients do not take their medications as intended. The present article explores a continuum of evaluation strategies and performance measures for assessing the effectiveness of community-based programs designed to enhance treatment completion in patients with active pulmonary tuberculosis. Four traditional evaluation strategies (case studies, retrospective and case-control studies, forecasting/modeling, and cost effectiveness analysis) and 2 emerging and promising approaches (quality of life assessment and indicators of the continuum of care) are presented. Several of the evaluation strategies reviewed indicate that treatment programs using directly observed therapy (DOT) that are comprehensive, community-based and patient-centered achieve the highest treatment completion rates. Combinations of these strategies are recommended to create a body of evidence capturing the impact and nuances of community-based public health interventions in improving health outcomes, in this case for patients with pulmonary tuberculosis.

The emerging crisis of drug-resistant tuberculosis in South Africa: lessons from New York City

Multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis have emerged as important infections in South Africa among patients infected with human immunodeficiency virus (HIV). In the face of this new epidemic, South Africa must rededicate itself to the task of tuberculosis control and treatment with a rapid, multifaceted approach. Priorities include expansion of second-line treatment capacity, investment in clinical laboratories, a system to ensure supervised treatment for all patients, and enhancement of infection control procedures. In New York City, where drug-resistant tuberculosis emerged 2 decades ago--also in the context of a large HIV-infected population and an underfunded public health infrastructure--similar steps were successful in leading to the rapid decrease in rates of drug resistance among tuberculosis isolates. With refinements based on local resource constraints, urgent measures could potentially arrest the alarming increase in multidrug-resistant and extensively drug-resistant tuberculosis cases in South Africa. Unlike many countries in sub-Saharan Africa, South Africa has the capacity to mount a rapid and large-scale response before drug-resistant tuberculosis envelops a much larger and far poorer region.

Treatment default among urban tuberculosis patients, Thailand

Tuberculosis treatment default, missing medical appointments for two consecutive months or more, is a serious problem not only for individuals but also for societies and health-care systems. Most research focuses only on patient factors without considering health-care system factors' effects on treatment default. The study purpose was to examine the influence of process of care on treatment default. Structured interviews and medical chart reviews were conducted in 160 tuberculosis patients receiving care at a tertiary hospital in Thailand. The samples included 54 patients with treatment default and 106 patients with treatment completion. Hierarchical logistic regression was used to examine relationships among the variables. After adjusting for patient factors, having severe medication side-effect and travel time to clinic increased treatment default. The patient factor of being paid on a daily basis was also significantly associated with treatment default. Evidence indicates that some process of care factors influence treatment default. Findings can be applied to practice levels to maintain patients until treatment completion.

Use of Community‐Based, Directly Observed Therapy for HIV Infection: Lessons Learned for Treatment of Hepatitis C Virus Infection

Directly observed therapy (DOT) is an effective approach for the treatment of tuberculosis among substance users. We have adapted this model to treat human immunodeficiency virus infection. Our experience suggests that community-based, modified DOT should be explored further as a means to treat infectious diseases and chronic medical illnesses for persons with drug dependence; it may be especially pertinent for the treatment of hepatitis C virus infection. DOT can both optimize adherence and provide a way to offer psychosocial support and linkages to social, addiction, psychiatric, and other services, to help address many of the challenges faced by persons with substance abuse disorders.

Developing a directly administered antiretroviral therapy intervention for HIV-infected drug users: implications for program replication

Directly administered antiretroviral therapy (DAART) is one approach to improving adherence to among human immunodeficiency virus (HIV)-infected drug users. We evaluated the essential features of a community-based DAART intervention in a randomized, controlled trial of DAART versus self-administered therapy. Of the initial 72 subjects, 78% were racial minorities, and 32% were women. Social and medical comorbidities among subjects included homelessness (35% of subjects), lack of interpersonal support (86%), major depression (57%), and alcoholism (36%). At baseline, the median CD4+ cell count was 403 cells/mL and the median HIV-1 RNA load was 146,333 copies/mL (log10 5.31 copies/mL). During the prior 6 months, 33% of subjects had missed a medical appointment, and 47% had visited an emergency department. Although most subjects (67%) preferred to take their own medications, 76% would accept DAART if it were made compulsory. A methadone clinic was the DAART venue acceptable to the fewest subjects (36%), and a mobile syringe-exchange program was acceptable to the most subjects (83%). Adherence was higher for supervised than for unsupervised medication administration (P<.0001), a finding that supports use of daily supervision of once-daily regimens. Moreover, DAART should incorporate enhanced elements such as convenience, flexibility, confidentiality, cues and reminders, responsive pharmacy and medical services, and specialized training for staff.

Utility of Tuberculosis Directly Observed Therapy Programs as Sites for Access to and Provision of Antiretroviral Therapy in Resource-Limited Countries

The overwhelming share of the global human immunodeficiency virus (HIV) infection and disease burden is borne by resource-limited countries. The explosive spread of HIV infection and growing burden of disease in these countries has intensified the need to find solutions to improved access to treatment for HIV infection. The epidemic of HIV infection and acquired immune deficiency syndrome (AIDS) has been accompanied by a severe epidemic of tuberculosis. Tuberculosis has become the major cause of morbidity and mortality in patients with HIV disease worldwide. Among the various models of provision of HIV/AIDS care, one logical but unexplored strategy is to integrate HIV/AIDS and tuberculosis care and treatment, including highly active antiretroviral therapy, through existing tuberculosis directly observed therapy programs. This strategy could address the related issues of inadequate access and infrastructure and need for enhanced adherence to medication and thereby potentially improve the outcome for both diseases.

Tuberculosis in New York city: recent lessons and a look ahead

In the late 1980s and early 1990s, after decades of decline, the incidence of tuberculosis began to rise in New York city, reaching a peak of 3811 cases by 1992. The epidemic took root in a setting of inadequate treatment regimens, homelessness, a diminished public-health system, and the onset of the HIV/AIDS epidemic. In addition, a subepidemic of drug-resistant tuberculosis occurred throughout New York city, most notably in a series of well documented nosocomial outbreaks. By 1994, using broadened initial treatment regimens, directly observed therapy, and improved US Centers for Disease Control and Prevention guidelines for hospital control and disease prevention, New York city began to effectively halt the progression of the epidemic. By 2002, tuberculosis rates in New York city reached an historic low of 1084. However, given the presence of a large reservoir of latently infected individuals in the city and an ongoing tuberculosis pandemic, New York city continues to face significant challenges from this persistent pathogen.

Directly observed therapy for the treatment of people with human immunodeficiency virus infection: a work in progress

The principle of directly observed therapy (DOT) has its roots in the treatment of tuberculosis (TB), for which DOT programs have improved cure rates in hard-to-reach populations. Human immunodeficiency virus (HIV) and TB affect similar populations, and there are concerns about both regarding the development of drug resistance associated with poor adherence to therapy. Accordingly, DOT may benefit certain HIV-infected people who have difficulty adhering to highly active antiretroviral therapy. However, important differences exist in the treatment of these diseases that raise questions about how DOT can be adapted to HIV therapy. DOT for management of HIV infection has been effective among prisoners and in pilot programs in Haiti, Rhode Island, and Florida. Although DOT can successfully treat HIV infection in marginalized populations in the short term, a multitude of questions remain. This review provides an account of the preliminary development of DOT programs for the treatment of HIV-infected individuals.

HIV drug adherence: special situations

Among the highly diverse population of persons living with HIV/AIDS are individuals with particularly challenging life circumstances that can be called "special situations." Substance abuse and homelessness are examples of special situations that require additional consideration when attempting to determine the appropriateness of prescribing complex antiretroviral regimens. When individual cases are examined in the context of relevant models of care and the principles of those models applied, such clinical decisions can be made with the patient. Withholding protease inhibitors from an entire population group, it is argued, is the epitome of practicing bad medicine.

Directly observed therapy and treatment adherence

Direct observation of patients taking their medication is a strategy to improve completion rates for tuberculosis treatment, but the programmes to implement this approach consist of a complex array of inputs aimed at influencing adherence. Policy makers need a clear understanding of these inputs to succeed. We systematically identified and reviewed published reports of direct observation therapy (DOT) programmes and compared inputs with WHO's short-course DOT programme. DOT programmes frequently consist of more than the five elements of WHO's strategy, including incentives, tracing of defaulters, legal sanctions, patient-centred approaches, staff motivation, supervision, and additional external funds. Focusing on direct observation as a key factor in the promotion of adherence seems inappropriate. Multiple components might account for the success of DOT programmes, and WHO should make these explicit.

Impact of medical and nonmedical factors on physician decision making for HIV/AIDS antiretroviral treatment

To examine influences of medical factors (e.g., viral load) and nonmedical factors (e.g., patient characteristics) on treatment decisions for highly active antiretroviral therapy (HAART), we sent a survey to a random sample of 995 infectious disease physicians who treat patients with HIV/AIDS in the United States in August, 1998. The response rate was 53%. Respondents were asked to report their current practices with respect to antiretroviral treatment and the extent to which each of three medical and 17 nonmedical factors would influence them for or against prescribing HAART to a hypothetical HIV-positive patient. Most reported initiating HAART with findings of low CD4+ cell counts and high viral loads, and weighing CD4+ cell counts, viral load, and opportunistic infection heavily in their decisions to prescribe HAART. Patients' prior history of poor adherence was weighed very much against initiating HAART. Patient homelessness, heavy alcohol use, injection drug use, and prior psychiatric hospitalization were cited by most physicians as weighing against HAART initiation. Thus, most physicians in this sample follow guidelines for the use of HAART, and nonmedical factors related to patients' life situations are weighed as heavily as disease severity in treatment decisions. As HIV increasingly becomes a disease associated with economic disadvantage and other social health problems, it will be essential to develop interventions and care support systems to enable patients experiencing these problems to benefit from HIV treatment advances.

Incentives and accessibility: a pilot study to promote adherence to TB prophylaxis in a high-risk community

SETTING

A community-based directly observed preventive therapy (DOPT) program for treatment of latent tuberculosis infection among injection drug users (IDUs) in an inner-city neighborhood.

OBJECTIVE

To test adherence to a 6-month course of DOPT using cash incentives and an easily accessible neighborhood location.

DESIGN

Street-recruited IDUs (N = 205) were screened for Mycobacterium tuberculosis (TB) infection using the Mantoux test and two controls. Subjects who had a purified protein derivative (PPD) reaction of > or =5 mm, were anergic, or had a history of a positive PPD received clinical evaluation at a community field site, provided in collaboration with the San Francisco Department of Public Health Tuberculosis Clinic. Twenty-eight subjects were considered appropriate candidates for prophylaxis with isoniazid, and 27 enrolled in the pilot study. Participants received twice-weekly DOPT at a community satellite office, with a $10 cash incentive at each visit.

RESULTS

The 6-month (26-week) regimen was completed by 24/27 (89%) participants. The median time to treatment completion was 27 weeks (range 26 to 34 weeks). The median proportion of dosing days attended in 6 months was 96%.

CONCLUSION

Community-based DOPT using cash incentives resulted in high levels of adherence and treatment completion among drug users.

Cost-effectiveness analysis of directly observed therapy for patients with tuberculosis at low risk for treatment default

To determine the incremental cost of directly observed therapy (DOT) for patients with tuberculosis at low risk for treatment default, we applied a model of DOT effectiveness to 1,377 low-risk patients in California during 1995. The default rate for this cohort, which consisted of those with no recent history of substance abuse, homelessness, or incarceration, was 1.7%. The model predicted that DOT and self-administered therapy (SAT) cured 93.1 and 90.8% of these patients, respectively. DOT would initially cost $1.83 million more than SAT, but avert $569,191 in treatment cost for relapse cases and their contacts, for a net incremental cost of $1.27 million ($919 per patient treated), or $40,620 per additional case cured. The cost-effectiveness of DOT was sensitive to the default rate and relapse rate after completing SAT. DOT would generate cost savings only when the default and relapse rates were more than 32.2 and 9.2%, respectively. Given the low default rate and resulting high incremental cost of DOT, provision of DOT to low-risk patients in California should be evaluated in the context of resource availability, competing program priorities, and program success in completing self-administered therapy with a low relapse rate.

Drug resistance in tuberculosis

Drug-resistant tuberculosis remains a worldwide problem. New laboratory methods have improved our ability to more rapidly identify resistant strains, but the most effective approach is to prevent the appearance of resistance by appropriate choice of antibiotics and directly-observed therapy. Mycobacterium tuberculosis is treated with familiar and unique drugs; consequently, mechanisms of resistance have some unique features. All drug resistance thus far identified develops by mutational events rather than acquisition of resistance genes from other bacteria. An agenda is presented for countering the appearance of further drug resistance in mycobacteria.

Adherence to prescribed HIV-1 protease inhibitors in the home setting

The issue of adherence to any therapy prescribed by a health care provider is multidimensional and includes personal challenges that exist in the daily life of any client, as well as the individual practices and attitudes of the health care provider. In addition, since most health is delivered in congregate settings such as the hospital, clinic, or office, it is important to consider those factors that may be present in a client's home that can impede compliant behavior. This article reviews challenges to compliance that should be considered when developing a care plan for clients, focusing on variables that may be present in the home setting.

Compliance/adherence and care management in HIV disease

With the changing perspectives of the HIV epidemic and the introduction of protease inhibitors to treat human immunodeficiency virus (HIV) disease, the issue of compliance has gained considerable interest among health care providers. The idea that clients with HIV disease should succumb to a patriarchal system of medical care has been challenged by AIDS activists since the beginning of the epidemic. The concept that there is only one explanation for "noncompliance" is outdated. The reasons for noncompliance are multifaceted in nature and include psychosocial factors, complex medication and treatment regimens, ethnocultural concerns, and in many instances substance use. Therefore, the notion that there is one intervention to resolve noncompliance is at best archaic. Interventions to enhance compliance include supervised therapy, improving the nurse-client relationship, and patient education, all of which should be combined with ethnocultural interventions. Plans to enhance compliance must incorporate person-specific variables and should be tailored to individualized needs.

The prevalence of hypertension in seven populations of west African origin

OBJECTIVES

This study was undertaken to describe the distribution of blood pressures, hypertension prevalence, and associated risk factors among seven populations of West African origin.

METHODS

The rates of hypertension in West Africa (Nigeria and Cameroon), the Caribbean (Jamaica, St. Lucia, Barbados), and the United States (metropolitan Chicago, Illinois) were compared on the basis of a highly standardized collaborative protocol. After researchers were given central training in survey methods, population-based samples of 800 to 2500 adults over the age of 25 were examined in seven sites, yielding a total sample of 10014.

RESULTS

A consistent gradient of hypertension prevalence was observed, rising from 16% in West Africa to 26% in the Caribbean and 33% in the United States. Mean blood pressures were similar among persons aged 25 to 34, while the increase in hypertension prevalence with age was twice as steep in the United States as in Africa. Environmental factors, most notably obesity and the intake of sodium and potassium, varied consistently with disease prevalence across regions.

CONCLUSION

The findings demonstrate the determining role of social conditions in the evolution of hypertension risk in these populations.