General HIV-Related Knowledge and Attitudes Among Nurses and Nursing Students: A Systematic Review and Meta-Analysis with Narrative Synthesis of Clinical Practices (2011–2026)

Background/Objectives: Nurses and nursing students are central to HIV prevention and care, but studies of their general HIV-related knowledge, attitudes, and practices use heterogeneous populations, instruments, scoring systems, and thresholds. This review had three objectives: (1) to meta-analyze, separately, the prevalence of study-defined high/good general HIV knowledge, mean general knowledge scores, prevalence of study-defined positive/favorable general attitudes, and mean favorable-attitude scores; (2) to synthesize HIV-related clinical-practice findings narratively when measures were not comparable; and (3) to explore whether pooled knowledge and attitude estimates differed between practicing nurses and nursing students. General outcomes excluded narrowly focused PrEP-, PEP-, stigma-only, and item-level constructs. Methods: PubMed/MEDLINE, Scopus, PsycINFO, and CINAHL Complete were searched for eligible quantitative studies. Four knowledge and attitude outcomes were meta-analyzed in separate random-effects models; practice outcomes were not pooled. Heterogeneity, 95% prediction intervals, leave-one-out influence, possible small-study effects, subgroup differences, and certainty of evidence were assessed. Results: Thirty-four studies were included. The pooled prevalence of high/good HIV-related knowledge was 52.4% (95% CI 30.4–73.5%; I2 = 97.5%; 95% prediction interval 3.6–97.0%), and the pooled mean knowledge score was 66.3% of the possible score (95% CI 60.8–71.8%; I2 = 99.8%; prediction interval 40.0–92.5%). Positive/favorable attitudes had a pooled prevalence of 41.6% (95% CI 7.3–86.5%; I2 = 99.1%; prediction interval 0.0–99.9%), and the pooled mean favorable-attitude score was 48.1% of the possible range (95% CI 41.9–54.2%; I2 = 99.7%; prediction interval 21.3–74.8%). Thus, all four meta-analyses showed extreme heterogeneity and wide prediction intervals. Prespecified subgroup tests did not detect nurse-versus-student differences for either knowledge outcome or favorable-attitude prevalence; a higher pooled mean favorable-attitude score among students was observed in one exploratory comparison. Four studies reported non-equivalent practice indicators (16.0–85.3%), which were not pooled. Certainty was very low for all meta-analyzed outcomes. Conclusions: The pooled estimates should be interpreted as descriptive summaries across heterogeneous operationalizations rather than as precise global nursing-workforce benchmarks or common competency thresholds. More standardized measurement, objective assessment of clinical practice, and longitudinal and interventional research are needed.