CKD of Uncertain Etiology: A Systematic Review

Background and objectives

Epidemics of CKD of uncertain etiology (CKDu) are emerging around the world. Highlighting common risk factors for CKD of uncertain etiology across various regions and populations may be important for health policy and public health responses.

Design, setting, participants, & measurements

We searched PubMed, Embase, Scopus and Web of Science databases to identify published studies on CKDu. The search was generated in January of 2015; no language or date limits were used. We used a vote-counting method to evaluate exposures across all studies.

Results

We identified 1607 articles, of which 26 met inclusion criteria. Eighteen (69%) were conducted in known CKDu–endemic countries: Sri Lanka (38%), Nicaragua (19%), and El Salvador (12%). The other studies were from India, Japan, Australia, Mexico, Sweden, Tunisia, Tanzania, and the United States. Heavy metals, heat stress, and dietary exposures were reported across all geographic regions. In south Asia, family history, agrochemical use, and heavy metal exposures were reported most frequently, whereas altitude and temperature were reported only in studies from Central America. Across all regions, CKDu was most frequently associated with a family history of CKDu, agricultural occupation, men, middle age, snake bite, and heavy metal exposure.

Conclusions

Studies examining etiologies of CKDu have reported many exposures that are heterogeneous and vary by region. To identify etiologies of CKDu, designing consistent and comparative multisite studies across high-risk populations may help elucidate the importance of region–specific versus global risk factors.     

Hantavirus Public Health Outreach Effectiveness in Three Populations: An Overview of Northwestern New Mexico,Los Santos Panama,and Region IX Chile

This research compared the effectiveness of Hantavirus Pulmonary Syndrome (HPS) outreach programs in New Mexico, Panama, and Chile. Understanding the role of human demographics, disease ecology, and human behavior in the disease process is critical to the examination of community responses in terms of behavior changes. Attitudes, knowledge, and behavior across three populations were measured through the implementation of a self-administered questionnaire (N = 601). Surveys implemented in Chile and Panama in 2004, followed by northwestern New Mexico in 2008, attempted to assess knowledge and behavior change with respect to hantavirus in high- and lower-risk prevalence areas during endemic periods. While levels of concern over contracting hantavirus were lowest in New Mexico, they were highest in Panama. Respondents in Chile showed mid-level concern and exhibited a tendency to practice proper cleaning methods more than in New Mexico and Panama. This indicates that public health messages appear to be more effective in Chile. However, since negative behavior changes, such as sweeping and vacuuming, occur at some level in all three populations, improved messages should help decrease risk of exposure to HPS.     

Community Health Workers and Environmental Interventions for Children with Asthma: A Systematic Review

Community health worker (CHW)–delivered, home-based environmental interventions for pediatric asthma were systematically reviewed. Seven PubMed/MEDLINE listed randomized controlled trials that encompassed the following intervention criteria were identified: (1) home-based; () delivered by a CHW; () delivered to families with children with asthma; and () addressed multiple environmental triggers for asthma. Details of research design, intervention type, and setting, interventionist, population served, and the evaluated outcomes were abstracted. Outcome assessment was broad and non-uniform. Categories included direct mediators of improved health outcomes, such as trigger-related knowledge, trigger reduction behaviors and allergen or exposure levels, and asthma-related health outcomes: change in lung function, medication use, asthma symptoms, activity limitations, and health care utilization. Indirect mediators of health outcomes, or psychosocial influences on health, were measured in few studies.

Overall, the studies consistently identified positive outcomes associated with CHW-delivered interventions, including decreased asthma symptoms, daytime activity limitations, and emergency and urgent care use. However, improvements in trigger reduction behaviors and allergen levels, hypothesized mediators of these outcomes, were inconsistent. Trigger reduction behaviors appeared to be tied to study-based resource provision. To better understand the mechanism through which CHW-led environmental interventions cause a change in asthma-related health outcomes, information on the theoretical concepts that mediate behavior change in trigger control (self-efficacy, social support) is needed. In addition, evaluating the influence of CHWs as clinic liaisons that enhance access to health professionals, complement clinic-based teaching, and improve appropriate use of asthma medications should be considered, alongside their effect on environmental management. A conceptual model identifying pathways for future investigation is presented.     

Work-Related Human T-lymphotropic Virus 1 and 2 (HTLV-1/2) Infection: A Systematic Review

Human T-lymphotropic virus 1 and 2 (HTLV-1/2) belong to the delta group of retroviruses which may cause a life-long infection in humans, HTLV-1 leading to adult T-cell leukemia/lymphoma and other diseases. Different transmission modes have been described, such as breastfeeding, and, as for other blood-borne pathogens, unsafe sexual activity, intravenous drug usage, and blood transfusion and transplantation. The present systematic review was conducted to identify all peer-reviewed studies concerning the work-related infection by HTLV-1/2. A literature search was conducted from January to May 2021, according to the PRISMA methodology, selecting 29 studies: seven related to health care workers (HCWs), five to non-HCWs, and 17 to sex workers (SWs). The findings showed no clear evidence as to the possibility of HTLV-1/2 occupational transmission in HCWs, according to the limited number and quality of the papers. Moreover, non-HCWs showed a higher prevalence in jobs consistent with a lower socioeconomic status or that could represent a familial cluster, and an increased risk of zoonotic transmission from STLV-1-infected non-human primates has been observed in African hunters. Finally, a general increase of HTLV-1 infection was observed in SWs, whereas only one paper described an increased prevalence for HTLV-2, supporting the urgent need for prevention and control measures, including screening, diagnosis, and treatment of HTLV-1/2, to be offered routinely as part of a comprehensive approach to decrease the impact of sexually transmitted diseases in SWs.     

Key Factors That Enable the Pandemic Potential of RNA Viruses and Inter-Species Transmission: A Systematic Review

Viruses play a primary role as etiological agents of pandemics worldwide. Although there has been progress in identifying the molecular features of both viruses and hosts, the extent of the impact these and other factors have that contribute to interspecies transmission and their relationship with the emergence of diseases are poorly understood. The objective of this review was to analyze the factors related to the characteristics inherent to RNA viruses accountable for pandemics in the last 20 years which facilitate infection, promote interspecies jump, and assist in the generation of zoonotic infections with pandemic potential. The search resulted in 48 research articles that met the inclusion criteria. Changes adopted by RNA viruses are influenced by environmental and host-related factors, which define their ability to adapt. Population density, host distribution, migration patterns, and the loss of natural habitats, among others, have been associated as factors in the virus–host interaction. This review also included a critical analysis of the Latin American context, considering its diverse and unique social, cultural, and biodiversity characteristics. The scarcity of scientific information is striking, thus, a call to local institutions and governments to invest more resources and efforts to the study of these factors in the region is key.     

SARS-CoV-2 and Its Variants in Thrice-Infected Health Workers: A Case Series from an Italian University Hospital

Background: We described a SARS-CoV-2 thrice-infected case series in health workers (HW) to evaluate patient and virus variants and lineages and collect information on variables associated with multiple infections. Methods: A retrospective analysis of clinical and laboratory characteristics of SARS-CoV-2 thrice-infected individuals was carried out in Verona University Hospital, concurrent with the ORCHESTRA project. Variant analysis was conducted on a subset of available specimens. Results: Twelve HW out of 7368 were thrice infected (0.16%). Symptomatic infections were reported in 63.6%, 54.5% and 72.7% of the first, second and third infections, respectively. Nine subjects were fully vaccinated at the time of the third infection, and five had an additional booster dose. The mean time to second infection was 349.6 days (95% CI, 138–443); the mean interval between the second and third infection was 223.5 days (95% CI, 108–530) (p = 0.032). In three cases, the second and third infections were caused by the Omicron variant, but different lineages were detected when the second vs third infections were sequenced. Conclusions: This case series confirms evidence of multiple reinfections with SARS-CoV-2, even from the same variant, in vaccinated HW. These results reinforce the need for continued infection-specific prevention measures in previously infected and reinfected HW.     

Behavioral Studies of Female Sex Workers in China: A Literature Review and Recommendation for Future Research

Commercial sex plays a critical role in the heterosexual transmission of HIV in China. This study reviews behavioral studies in English literature on female sex workers (FSWs) in China from 1990 to 2006. Existing studies indicate that FSWs in China are young, mobile, most of them have both commercial and non-commercial sex partners; they have low rates of consistent condom use and high rates of STD infection. Some FSWs are also engaged in drug abuse. There is a great variation of sexual practices and HIV risks among FSWs across different work settings. Limited numbers of intervention studies have reported positive effects on increasing condom use and/or decreasing STD infections. Literature gaps and lessons learned from existing studies are identified and future research needs are discussed. Future behavioral intervention programs need to be multi-faceted and incorporate environmental and structural factors for different groups of FSWs.     

Prevention and Treatment of Monkeypox: A Systematic Review of Preclinical Studies

The outbreak of monkeypox, coupled with the onslaught of the COVID-19 pandemic is a critical communicable disease. This study aimed to systematically identify and review research done on preclinical studies focusing on the potential monkeypox treatment and immunization. The presented juxtaposition of efficacy of potential treatments and vaccination that had been tested in preclinical trials could serve as a useful primer of monkeypox virus. The literature identified using key terms such as monkeypox virus or management or vaccine stringed using Boolean operators was systematically reviewed. Pubmed, SCOPUS, Cochrane, and preprint databases were used, and screening was performed in accordance with PRISMA guidelines. A total of 467 results from registered databases and 116 from grey literature databases were screened. Of these results, 72 studies from registered databases and three grey literature studies underwent full-text screening for eligibility. In this systematic review, a total of 27 articles were eligible according to the inclusion criteria and were used. Tecovirimat, known as TPOXX or ST-246, is an antiviral drug indicated for smallpox infection whereas brincidofovir inhibits the viral DNA polymerase after incorporation into viral DNA. The ability of tecovirimat in providing protection to poxvirus-challenged animals from death had been demonstrated in a number of animal studies. Non-inferior with regard to immunogenicity was reported for the live smallpox/monkeypox vaccine compared with a single dose of a licensed live smallpox vaccine. The trial involving the live vaccine showed a geometric mean titre of vaccinia-neutralizing antibodies post two weeks of the second dose of the live smallpox/monkeypox vaccine. Of note, up to the third generation of smallpox vaccines—particularly JYNNEOS and Lc16m8—have been developed as preventive measures for MPXV infection and these vaccines had been demonstrated to have improved safety compared to the earlier generations.     

Drought,drying and climate change: Emerging health issues for ageing Australians in rural areas

Older Australians living in rural areas have long faced significant challenges in maintaining health. Their circumstances are shaped by the occupations, lifestyles, environments and remoteness which characterise the diversity of rural communities. Many rural regions face threats to future sustainability and greater proportions of the aged reside in these areas. The emerging changes in Australia's climate over the past decade may be considered indicative of future trends, and herald amplification of these familiar challenges for rural communities. Such climate changes are likely to exacerbate existing health risks and compromise community infrastructure in some instances. This paper discusses climate change‐related health risks facing older people in rural areas, with an emphasis on the impact of heat, drought and drying on rural and remote regions. Adaptive health sector responses are identified to promote mitigation of this substantial emerging need as individuals and their communities experience the projected impact of climate change.     

Maintaining population health in low- and middle-income countries during the COVID-19 pandemic: Why we should be investing in Community Health Workers

Community health workers in low- and middle-income country primary health care systems are well suited to perform essential functions on the frontlines of Covid-19 pandemic responses. However, clear and coordinated guidance, updated infection control training, and reliable access to personal protective equipment must be ensured in order to deploy them safely and effectively. With these additional responsibilities, community health workers must also be supported to ensure that hard-fought gains in population health, including progress on non-communicable diseases, are sustained throughout the pandemic.     

Fish Consumption and Cardiovascular Health: A Systematic Review

Studies evaluating fish consumption and cardiovascular disease events have shown inconsistent results. We performed a systematic review of peer-reviewed publications from an extensive query of Ovid MEDLINE, Ovid Embase, Ovid Cochrane Database of Systematic Reviews, Scopus, and Web of Science from database inception to September 2020 for observational studies that reported the association between fish consumption and cardiovascular disease events. We identified and reviewed 24 studies related to fish consumption and the effect on cardiovascular outcomes. The study population included a total of 714,526 individuals and multiple cohorts from several countries. We found that nonfried fish consumption is probably associated with a reduced risk of overall cardiovascular disease events and myocardial infarction risk. In contrast, fried fish consumption is probably associated with an increased risk of overall cardiovascular disease events and myocardial infarction risk. No studies to date have shown any significant association between fish consumption and stroke. Our analysis suggests that fish consumption may reduce cardiovascular disease events, but fried fish consumption was associated with an increased risk of cardiovascular events.     

From the Cover: Health benefits of decreases in on-road transportation emissions in the United States from 2008 to 2017

Decades of air pollution regulation have yielded enormous benefits in the United States, but vehicle emissions remain a climate and public health issue. Studies have quantified the vehicle-related fine particulate matter (PM_2.5)-attributable mortality but lack the combination of proper counterfactual scenarios, latest epidemiological evidence, and detailed spatial resolution; all needed to assess the benefits of recent emission reductions. We use this combination to assess PM_2.5-attributable health benefits and also assess the climate benefits of on-road emission reductions between 2008 and 2017. We estimate total benefits of $270 (190 to 480) billion in 2017. Vehicle-related PM_2.5-attributable deaths decreased from 27,700 in 2008 to 19,800 in 2017; however, had per-mile emission factors remained at 2008 levels, 48,200 deaths would have occurred in 2017. The 74% increase from 27,700 to 48,200 PM_2.5-attributable deaths with the same emission factors is due to lower baseline PM_2.5 concentrations (+26%), more vehicle miles and fleet composition changes (+22%), higher baseline mortality (+13%), and interactions among these (+12%). Climate benefits were small (3 to 19% of the total). The percent reductions in emissions and PM_2.5-attributable deaths were similar despite an opportunity to achieve disproportionately large health benefits by reducing high-impact emissions of passenger light-duty vehicles in urban areas. Increasingly large vehicles and an aging population, increasing mortality, suggest large health benefits in urban areas require more stringent policies. Local policies can be effective because high-impact primary PM_2.5 and NH₃ emissions disperse little outside metropolitan areas. Complementary national-level policies for NO_x are merited because of its substantial impacts—with little spatial variability—and dispersion across states and metropolitan areas.

Health impacts of air pollution from transportation remain a major public health problem in the United States with several studies estimating roughly 17,000 to 20,000 deaths/year attributable to it in recent years, the vast majority from fine particulate matter (PM_2.5) (1–4). Researchers have used different methods to estimate this burden, limiting comparability among estimates, but those who have estimated attributable deaths in different years have shown this burden has decreased. Dedoussi et al. (3) estimate that they were cut in half in the 2005 to 2018 period, from 37,000 to 18,400 due to PM_2.5 and ozone, whereas Fann et al. (1) estimate just under 30,000 in 2005 and 19,300 in 2016, a decrease of about a third. These studies’ estimates for 2016 and 2018, however, rely on forecasts of emissions made years in advance.Transportation emissions also contribute to climate impacts. Transportation greenhouse gas (GHG) emissions have increased in recent years, and they were responsible for 28% of the US GHG emissions in 2018 (5). A total of 83% of transportation GHG emissions in 2018 came from vehicles, and 70% of vehicle GHG emissions came from light-duty vehicles (LDVs) (5). In recent years, LDV energy efficiency has increased and GHG emission factors per mile (EF) decreased, but their overall climate impacts have increased (5, 6). Increased market penetration of larger LDVs (6) and increased vehicle miles traveled (VMT) (7) have contributed to this overall increase.Decades of environmental regulation in the United States have drastically reduced emissions from vehicles by as much as 99% per vehicle for common pollutants since 1970 (8). Transportation emissions are one element of a substantial effort to reduce ambient PM_2.5 in recent decades (9, 10), following regulation of air pollution that has been cost-beneficial and has yielded substantial benefits. The US Environmental Protection Agency (EPA) (11) estimates that the Clean Air Act Amendments of 1990 have yielded $2 trillion/year (2006 US dollars) in benefits from all sectors in 2020, or 30 times its cost, with 90% of the benefits coming from reduced PM_2.5-attributable mortality. Fuel efficacy standards and vehicle emission controls have been responsible for a substantial part of these benefits.Benefits of recent reductions in vehicle emissions, on the other hand, are not well understood. Several studies have quantified mortality from on-road transportation in recent years (1–4, 12–15), some of them also assessing changes over time and showing decreases. To our knowledge, however, no study has carried out a fine-scale assessment relying on counterfactual scenarios that capture changes in fleet composition and VMT, population, age-specific baseline mortality rates, and lower ambient PM_2.5 concentrations at baseline. The latter is important because more recent epidemiological evidence from the Global Exposure Mortality Model (GEMM) (16) suggests a nonlinear function linking ambient PM_2.5 concentration to mortality. The GEMM concentration–response function (CRF) is concave, exhibiting higher marginal effects at lower concentrations. As ambient PM_2.5 concentrations in the United States have dropped in recent decades (10), this nonlinearity suggests marginal effects are increasing over time. The previously widely used Global Burden of Disease (GBD) Integrated Exposure-Response (IER) model (17, 18) also estimated a concave CRF, but GEMM estimates more than twice as many attributable deaths for the United States and Canada when compared to GBD IER. GEMM also includes more recent evidence from epidemiological studies of populations in the two countries that allow it to estimate mortality risks for exposures to very low ambient PM_2.5 concentrations—as low as 2.4 μg/m³, lower than previous models—that are relevant for policies in the United States.Vehicle impacts also exhibit large spatial variability across states and cities (19, 20). Metropolitan areas are especially important because previous research has suggested that impacts per mile of passenger vehicles driving in these areas are large (20), and passenger transportation is now responsible for more PM_2.5-attributable deaths in the United States than truck use (4). Spatial variability in impact suggests a potential for more stringent policies in metropolitan areas where impacts are higher, but considering local policies would require understanding local impacts versus those transported to and affecting populations in other areas. Previous research has shown that over a third of impacts caused by all vehicle emissions in the United States occur across state lines, mostly from NO_x emissions (3); nevertheless, transfers of impacts caused by vehicles in metropolitan areas are not well studied.This paper assesses benefits of recent emissions reductions of on-road transportation in the contiguous United States occurring between 2008 and 2017. We assess impacts on a fine scale using a nonlinear CRF from the most recent epidemiological evidence from GEMM (16). We combine 1-km–resolution baseline ambient PM_2.5 levels (21), fine-scale (1 km in densely populated areas) air pollution modeling (2, 22), and county-level age- and cause-specific mortality (23). We assess impacts in 2017 for four counterfactual emission scenarios (2008 EFs, 2011 EFs, 2014 EFs, and 2017 EFs), each using county-level EFs for each pollutant and 13 vehicle types from the respective year’s National Emissions Inventory (NEI) (24–27). Our combination of fine-scale modeling and counterfactual emission scenarios allows us to capture changes in demographics, fleet composition, and baseline ambient PM_2.5 levels. We estimate benefits from decreases in PM_2.5-attributable mortality due to reductions in on-road transportation emissions of primary PM_2.5, SO₂, NO_x, NH₃, and volatile organic compounds (VOCs) (air pollution) and climate benefits from reductions in on-road transportation emissions of CO₂, CH₄, and N₂O (GHGs). As passenger vehicles were previously estimated to be responsible for most of the burden, we present a spatially explicit analysis of passenger LDVs with a focus on 53 large metropolitan statistical areas (MSAs), which we define as those with population exceeding 1 million in 2017 according to the US Census Bureau (28). In 2017, these 53 MSAs accounted for 56% of the US population (29) and 50% of the US VMT from all road vehicles (27). We refer to these large MSAs simply as MSAs or metropolitan areas throughout the paper.     

Health Technologies for Monitoring and Managing Diabetes: A Systematic Review

Background

The primary objective of this review was to determine the strength of evidence for the effectiveness of self-monitoring devices and technologies for individuals with type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM) based on specific health-related outcome measures. Self-monitoring devices included those that assist patients with managing diabetes and preventing cardiovascular complications (CVCs). A secondary objective was to explore issues of feasibility, usability, and compliance among patients and providers.

Methods

Study criteria included individuals ≥14 years and youth (7–14 years) with T1DM or T2DM, intervention with a self-monitoring device, assessment of clinical outcomes with the device, literature in English, and ≥10 participants. Relevant published literature was searched from 1985 to 2008. Randomized controlled trials and observational studies were included. Data were extracted for clinical outcomes, feasibility and compliance methods, and results. Selected studies were independently evaluated with a validated instrument for assessing methodological quality.

Results

Eighteen trials were selected. Predominant types of device interventions included self-monitoring of blood glucose, pedometers, and cell phone or wireless technologies. Feasibility and compliance were measured in the majority of studies.

Conclusions

Self-monitoring of blood glucose continues to be an effective tool for the management of diabetes. Wireless technologies can improve diabetes self-care, and pedometers are effective lifestyle modification tools. The results of this review indicate a need for additional controlled trial research on existing and novel technologies for diabetes self-monitoring, on health outcomes associated with diabetes and CVCs, and device feasibility and compliance.     

Mushroom Consumption and Cardiovascular Health: A Systematic Review

IntroductionEdible mushrooms have a great nutritional value including high protein, essential amino acids, fiber, vitamins (B₁, B₂, B₁₂, C, and D), minerals (calcium [Ca], potassium [K], magnesium [Mg], sodium [Na], phosphorus [P], copper [Cu], iron [Fe], manganese [Mn], and selenium [Se]), low fatty foods, and sodium. The objective of this systematic review was to determine the relationship between edible mushroom consumption and overall cardiovascular risk.MethodsWe systematically searched Ovid MEDLINE, Embase, Ovid Cochrane Database of Systematic Reviews, Scopus, and Web of Science from database inception from 1966 through August 2020 for observational studies that reported the association between edible mushroom consumption and cardiovascular risk. Two investigators independently reviewed data. Conflicts were resolved through consensus discussion.ResultsOf 1479 studies, we identified 7 prospective studies. Edible mushroom consumption may have favorable effects on lipid profiles by changing some metabolic markers such as low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, total cholesterol, and triglycerides. Moreover, edible mushroom consumption is probably associated with reduced mean blood pressure. The beneficial overall cardiovascular risk, stroke risk, and coronary artery disease of edible mushroom consumption are not consistent.ConclusionsEdible mushroom consumption has not been shown to conclusively affect cardiovascular risk factors to date. However, potential health benefits may exist, including a favorable alteration of lipid profiles and blood pressure reduction.     

Epidemiology of Cardiovascular Diseases in Morocco: A Systematic Review

OBJECTIVETo provide a systematic review of studies on cardiovascular diseases (CVD) and their risk factors in the Moroccan population.METHODSA systematic analysis was performed based on PRISMA guidelines by retrieving data bases (Medline, Embase, and other) using technical keywords in addition to manual research on official websites. Published studies in the English or French language, conducted in Morocco or concerning the Moroccan population within the last two decades, were identified.RESULTSThis is the first systematic review of CVD in Morocco. Data from 159 studies were retrieved and analyzed. Most studies were written in the English language (75.89%) and published between 2010 and 2019 (85.47%). The mortality rate caused by CVD in Morocco has reached 38%, with ischemic heart disease and stroke as the main events causing death (31.0% and 22.5% respectively). The risk factors present in the population studied were headed by tobacco smoking (45-50%), followed by physical inactivity (21.1%), elevated rate of hypertension (25.3%), and depression (5.47%). Impacted by a high rate of illiteracy and poverty and an unprepared health care system in Morocco, these numbers are expected to increase over the next decade.CONCLUSIONSBased on these alarming incidences, investment in scientific research and epidemiological studies should be increased to determine the needs of the local population. The available evidence shows that the risk of cardiovascular disease and the associated mortality is very high in Morocco and will rise in the next years prospectively, which calls for urgent multi-sectorial approaches and treatment strategies.     

The Relationship between Self-Efficacy,Functional Exercise Capacity and Physical Activity in People with COPD: A Systematic Review and Meta-Analyses

Abstract

The purpose of this study was to investigate the strength of the relationships between self-efficacy and (i) functional exercise capacity and (ii) physical activity in chronic obstructive pulmonary disease (COPD), and whether self-efficacy assessment type (i.e., COPD symptoms, exercise-task, exercise-barrier, general, falls) and physical activity assessment type (i.e., self-report vs. objective) are moderators. A systematic search of COPD and self-efficacy concepts was conducted using eight databases from inception to 23 January 2019. Studies were included if they provided correlation coefficients of the relationship between self-efficacy and functional exercise capacity or physical activity, were conducted in adults diagnosed with COPD, and were published in English-language journals. A total of 14 correlation coefficients were included in the self-efficacy and functional exercise capacity meta-analysis, and 16 in the self-efficacy and physical activity meta-analysis. Data were screened, reviewed, and extracted independently by two reviewers, with discrepancies resolved by a third reviewer. Stronger self-efficacy was associated with better functional exercise capacity (weighted r?=?0.38, 95%CI [0.25, 0.50]), and greater physical activity (weighted r?=?0.25, 95%CI [0.17, 0.34]). Exercise-task self-efficacy had the strongest relationship to functional exercise capacity (weighted r?=?0.64, 95% CI [0.51, 0.73]). For physical activity, the type of self-efficacy most strongly related was inconclusive. In COPD, self-efficacy has a relationship to functional exercise capacity and physical activity, the strength of which is influenced by the choice of self-efficacy measure. An understanding of these relationships will assist clinicians in selecting the self-efficacy measure most closely related to the outcome of interest.