The mental health of primary healthcare (PHC) workers influences the quality and sustainability of services within the Brazilian Unified Health System (SUS). Observational studies in Brazil report symptoms of common mental disorders, anxiety, depression, burnout, insomnia and stress among PHC workers, but the evidence is fragmented across settings, occupational groups, instruments and time periods. This protocol describes a systematic review and prevalence meta-analysis designed to consolidate prevalence estimates and to synthesise sociodemographic, occupational and organisational factors associated with these mental health outcomes among PHC workers in Brazil.
The primary objective is to estimate pooled prevalences for symptoms of common mental disorders, anxiety, depression, burnout, insomnia and stress among workers linked to PHC in Brazil. Secondary objectives are to identify and synthesise sociodemographic, occupational and organisational factors associated with these outcomes and to explore heterogeneity across studies by geographic region, occupational category, instrument and period of data collection.
Included studies must be quantitative observational studies conducted in Brazil and involve workers linked to PHC within the SUS. This includes health professionals as well as other occupational categories such as community health workers and administrative or operational staff. Studies must report prevalence estimates based on instruments validated for use in Brazilian populations and must state explicit case definitions or cut-offs for each outcome: common mental disorders, anxiety symptoms, depression, burnout, insomnia and stress.
The review searched bibliographic databases from inception to 16 September 2025: MEDLINE (via PubMed), Embase, PsycINFO, CINAHL and BVS/LILACS. These searches were complemented by grey literature searches in Google Scholar and the CAPES Theses and Dissertations repository, and by screening reference lists of included studies. The protocol specifies these sources as the basis for comprehensive retrieval of relevant prevalence studies.
Two independent reviewers will perform title/abstract and full-text screening using Rayyan. Discrepancies will be resolved by consensus or, if needed, by a third reviewer. Eligible data items to be extracted include prevalence estimates, instrument and cut-off used, study setting and region, occupational category, sampling method, sample size and period of data collection. The protocol documents procedures for managing records and for ensuring independent review at both screening stages.
Risk of bias in prevalence studies will be assessed with the Joanna Briggs Institute checklist for prevalence studies. The protocol indicates that assessments will inform sensitivity analyses and interpretation of pooled estimates but does not specify any arbitrary thresholds for exclusion based on bias scores; details beyond the chosen tool were not reported in the source.
Prevalence estimates will be pooled by outcome using random-effects meta-analysis. The primary analytic approach will employ binomial models. Between-study heterogeneity will be quantified using I², τ² and the Q statistic, and prediction intervals will be calculated to reflect expected range of prevalences in new settings. The protocol states these methods as the plan for producing summary prevalence measures while accommodating heterogeneity typical of observational prevalence research.
Prespecified subgroup and sensitivity analyses will explore potential sources of heterogeneity and include: geographic region within Brazil, occupational category (for example, clinicians versus community health workers or administrative staff), measurement instrument and cut-off used, sampling approach and risk of bias. Data collection period will be classified as prepandemic, pandemic/postpandemic, or mixed; analyses will evaluate prevalence differences according to these periods. The protocol sets these subgroup analyses to assess how contextual and methodological factors influence pooled prevalence estimates.
Sociodemographic, occupational and organisational factors associated with mental health outcomes will be synthesised as a structured narrative organised by domain. The protocol states that meta-analysis of associations (for example, pooled effect measures for particular exposures) will be considered only when exposure definitions and effect estimates are sufficiently comparable across studies. Where pooling is not feasible, the review will report and discuss the pattern of associations descriptively, noting consistency and limitations of the available evidence.
Ethics approval is not required for this review because it uses secondary data from published reports. For questions related to research integrity, the protocol provides a contact: the Research Ethics Committee of the Federal University of Espírito Santo (cep.ufes@hotmail.com). The authors plan to disseminate findings via publication in a peer-reviewed journal and presentations at scientific meetings.
Note: This document is a protocol describing planned methods for a systematic review and prevalence meta-analysis. Specific study-level results, pooled prevalence values, and detailed risk-of-bias outcomes are not reported here because this source presents the protocol rather than completed review findings.