Multilevel analyses of the cardiometabolic health of Indigenous Brazilian peoples

The Lancet published a very interesting Article by Caroline K Kramer and colleagues on urbanisation and health among Brazilian Indigenous People.1Kramer CK Leitão CB Viana LV The impact of urbanisation on the cardiometabolic health of Indigenous Brazilian peoples: a systematic review and meta-analysis, and data from the Brazilian Health registry.Lancet. 2022; 400: 2074-2083Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar In a systematic review and meta-analysis, the authors found that urbanisation level is associated with an increase in cardiometabolic adverse events. This type of evidence, as well as multilevel studies with individual data and context variables when heterogeneous results are observed, suggests effects of social determinants. However, the analysis performed by Kramer and colleagues also revealed the existence of the psychologistic fallacy among the studies included in the systematic review. This fallacy is often forgotten by epidemiologists who privilege individual data, denying that social determinants have heterogeneous effects on different social groups. The psychologistic fallacy occurs when contextual or ecological variables are not incorporated and inferences are made based exclusively on individual variables.2Diez Roux AV A glossary for multilevel analysis.J Epidemiol Community Health. 2002; 56: 588-594Crossref PubMed Scopus (416) Google Scholar These facts should be enough to encourage the study of social determinants in multilevel or multicentre studies.3Seifirad S Alquran L The bigger, the better? When multicenter clinical trials and meta-analyses do not work.Curr Med Res Opin. 2021; 37: 321-326Crossref Scopus (4) Google Scholar, 4Basagaña X Pedersen M Barrera-Gómez J et al.Analysis of multicentre epidemiological studies: contrasting fixed or random effects modelling and meta-analysis.Int J Epidemiol. 2018; 47: 1343-1354Crossref PubMed Scopus (36) Google Scholar However, systematic reviews with analyses stratified by the levels of a social determinant could be a better option because it can include many more contexts, representing different populations and social realities. The discussion about statistical analyses of fixed or random effects must be overcome, and we must begin to think from a multilevel logic where social determinants are important drivers of health conditions. The PRISMA statement5Page MJ McKenzie JE Bossuyt PM et al.The PRISMA 2020 statement: an updated guideline for reporting systematic reviews.BMJ. 2021; 372: n71Crossref PubMed Scopus (18443) Google Scholar could incorporate the exploration of social determinants involved when a heterogeneous effect is observed. This exploration would not be a simple stratified analysis but should be based on theoretical models from the social sciences. I declare no competing interests. The impact of urbanisation on the cardiometabolic health of Indigenous Brazilian peoples: a systematic review and meta-analysis, and data from the Brazilian Health registryThe macrosocial changes of Indigenous peoples’ traditional ways of living consequent to urbanisation are associated with an increased prevalence of adverse cardiometabolic outcomes. These data highlight the urgent need for environmental policies to ensure the conservation of the natural ecosystem within Indigenous territories, as well as the development of socio-health policies to improve the cardiovascular health of Indigenous Brazilians peoples living in urban areas. Full-Text PDF Multilevel analyses of the cardiometabolic health of Indigenous Brazilian peoples – Authors' replyWe thank Carlos E A Coimbra Jr and colleagues and Alvaro J Idrovo for their interest in our publication1 in which we showed an association between adverse cardiovascular health of Indigenous Brazilian Peoples and urbanisation with data obtained from systematic reviews and meta-analysis, the Brazilian census,2 and national death records. We also showed the effects of Amazon deforestation. The impact of urbanisation on cardiovascular risk was consistently evident on diverse epidemiological analyses, with independent proxies of urbanisation: meta-analyses of cardiovascular risk factors by geographical region (as shown in figure 1 of our paper); meta-regression analyses of cardiovascular risk over time (as shown in figure 1 of our paper); the prevalence of obesity and hypertension related to the proportion of Amazon rainforest in a territory (as shown in figure 2 of our paper); the trend in blood pressure levels in communities with diverse nutritional characteristics (as shown in figure 3 of our paper); age-adjusted cardiovascular mortality by geographical regions (as shown in figure 4 of our paper), including data from rural and urban settings as defined by the Brazilian census2 (as shown in the appendix [p 11] of our paper); and incremental change in cardiovascular deaths over time by geographical regions (as shown in figure 4 of our paper). Full-Text PDF