Awareness, Knowledge, and Self-Reported Clinical Experiences Related to Glucose-6-Phosphate Dehydrogenase Deficiency in Sardinia (Italy): A Descriptive Cross-Sectional Survey

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymatic disorder of red blood cells, with particularly high prevalence in Sardinia, where it is strongly associated with favism. Public awareness remains incomplete and misconceptions persist—particularly regarding symptom onset from fava bean pollen or odors. This cross-sectional survey assessed G6PD self-reported deficiency, population knowledge, and persistence of false beliefs in Sardinia. Methods: A 16-item structured questionnaire was disseminated online (May–June 2025) to adults across diverse age groups and educational backgrounds. Results: Among 536 respondents (74.25% female; 97.39% Sardinia residents), 43.47% of respondents self-reported as G6PD-deficient, a figure substantially above the expected population estimate of 8–15% and consistent with affected-network recruitment. Moreover, 49.07% self-reported as non-deficient, and 7.46% were unaware of their status. While 99.07% correctly identified fava bean ingestion as a trigger and 74.25% identified certain medications, 62.50% incorrectly attributed hazard to pollen inhalation and 25.93% to pea consumption. Only 3.92% reported a hemolytic crisis, whereas 25.93% reported feeling unwell after smelling beans or inhaling pollen. Family and friends (49.81%) and healthcare providers (42.16%) were the primary information sources; schools (25.75%) and online resources (14.55%) were underrepresented. Overall, 90.45% perceived public information as insufficient—uniformly across G6PD strata (χ2 = 0.09, p = 0.955). Exploratory analyses suggested lower perceived information adequacy among younger respondents (Cochran–Armitage Z = 2.92, p = 0.002) and, less robustly, among female respondents (χ2 = 3.90, p = 0.048; borderline significance, unadjusted). Conclusions: Although recognition of fava bean ingestion as the principal dietary trigger is nearly universal, substantial gaps persist regarding non-ingestive exposures, less-recognized dietary triggers, and pharmacological risks. Perceived information insufficiency was independent of G6PD status but associated with younger age and female sex. Integrating targeted nutritional education into school curricula, primary care, and digital platforms is warranted for these priority groups and for G6PD-endemic populations worldwide.