Multilingual Community Health Workers and Preventive Care Gaps in South Asian Immigrant Populations: A Scoping Review

Technical Summary: Multilingual Community Health Workers and Preventive Care Gaps in South Asian Immigrant Populations

Problem Statement
South Asian immigrants in the United States (defined as individuals of Indian, Pakistani, Bangladeshi, Sri Lankan, and Nepali origin) represent a rapidly growing demographic with disproportionately high risks for type 2 diabetes and cardiovascular disease, often manifesting at lower body mass index thresholds than standard guidelines suggest. Despite these elevated risks, this population consistently underutilizes preventive care services. Federally Qualified Health Centers (FQHCs) serve as a critical safety net for these communities, particularly in major urban centers like New York City. Community Health Workers (CHWs), who often share linguistic and cultural backgrounds with patients, have been proposed as a mechanism to bridge these preventive care gaps. However, the extent and nature of the evidence supporting CHW interventions specifically for South Asian immigrants within US safety-net settings remained unclear, necessitating a systematic mapping of the available literature.

Methodology
This study employed a scoping review methodology following the five-stage framework of Arksey and O'Malley, refined by Levac et al., and reported according to PRISMA-ScR guidelines. The review targeted literature published in English between January 2000 and December 2023.

• Search Strategy: Databases searched included PubMed/MEDLINE, Scopus, and CINAHL.
• Inclusion Criteria: Studies were included if they:
  • Involved adult South Asian immigrants or diverse immigrant populations with an identifiable South Asian subgroup.
  • Described a CHW or patient navigator intervention.
  • Were conducted within United States FQHCs or primary care safety-net settings.
  • Reported at least one preventive care outcome or protocol.
• Exclusion Criteria: Studies conducted outside the US, those lacking a CHW component, or those without primary data were excluded.
• Screening Process: The initial search yielded 164 records. After removing 14 duplicates, 150 unique records underwent title and abstract screening. Twelve records were deemed potentially relevant and underwent full-text verification. Five were excluded because they were conducted outside the United States (four in Hong Kong, one in Canada), despite containing "South Asian" in their titles. This left a final sample of seven studies.

Key Results
The final sample of seven studies revealed a narrow and geographically concentrated evidence base:

• Geographic Concentration: Six studies were based in New York City, and one was based in Boston.
• Study Designs: The sample included two completed Randomized Controlled Trials (RCTs), three RCT protocols (describing planned interventions without published outcomes), one mixed-methods implementation study, and one systematic review.
• Intervention Models: A recurring model involved pairing Electronic Health Record (EHR)-driven patient identification with coaching delivered by CHWs. This was piloted through two overlapping initiatives: the DREAM Initiative (focusing on diabetes) and Project IMPACT (focusing on hypertension).
• Outcomes:
  • Only one study (Islam et al., an RCT of 303 patients across 14 NYC practices) reported completed clinical outcomes from a CHW-led intervention specifically within a confirmed South Asian population. This trial demonstrated the feasibility of CHW-led coaching and group education for hypertension management.
  • Three studies were protocols with no published outcomes within the review window.
  • One study reported only implementation/organizational outcomes.
  • One RCT (Percac-Lima et al.) evaluated colorectal screening in a non-South-Asian-specific minority group.
  • One systematic review synthesized data from 15 US studies on patient navigators but did not disaggregate findings by South Asian subgroups.
• Methodological Observation: Five studies initially appeared relevant during title screening due to the pairing of "South Asian" and "Community Health Worker" but were excluded upon full-text review because they were conducted in Hong Kong or Canada. This highlights a specific pitfall in keyword-based screening for diaspora populations, where geographic context is easily conflated.

Key Contributions
The paper makes two primary contributions to the literature:

1. Evidence Base Clarification: It demonstrates that the evidence supporting CHW interventions for preventive care gaps in confirmed US South Asian immigrant populations is significantly narrower than initial title-level screening suggests. The current evidence rests substantially on a single completed trial and one overlapping research program (DREAM and Project IMPACT).
2. Methodological Insight: It identifies a specific methodological challenge in scoping reviews of diaspora populations: keyword-based title screening can conflate evidence from distinct national healthcare systems (e.g., US vs. Canada/Hong Kong). The review emphasizes that full-text verification of the geographic setting is essential to ensure the relevance of findings to US policy contexts.

Significance and Claims
The paper concludes that while a CHW-EHR integrated coaching model shows promise for hypertension management in South Asian populations, the current evidence base is insufficient to support broad, national programmatic recommendations for FQHCs. The authors assert that the generalizability of findings is limited by the small, concentrated pool of studies and the lack of data disaggregated by national-origin subgroups or CHW language concordance.

The significance of the work lies in its call for further geographically diverse research and completed-outcome studies before definitive conclusions can be drawn. The paper does not claim that CHW interventions are definitively proven to work across all South Asian subgroups or settings; rather, it positions the current findings as an "emerging evidence base" that requires expansion to inform future FQHC program design.