Effectiveness of training on vertigo/dizziness coding in primary care: a community-based cluster-randomized trial

BACKGROUND: Most patients with vertigo receive unspecific diagnoses, delaying treatment and causing unnecessary tests. Training primary care (PC) physicians is essential to improve accuracy. This study evaluates the effectiveness of an online training program with a face-to-face session on new specific diagnoses in PC. METHODS: A multicenter, open-label, cluster-randomized controlled community trial (control group [CG]/ intervention group [IG]) in twenty PC centers in southern Barcelona province (10 per group) was conducted to evaluate the effectiveness of the intervention under real-world primary care conditions. IG professionals received 14 h of online training and one face-to-face session on vertigo management. The primary outcome was the description of new specific vertigo diagnoses. Secondary outcomes included the unspecific, and any vertigo/dizziness diagnoses, the description of individual specific diagnoses (benign paroxysmal positional vertigo [BPPV], Meniere's disease, vestibular neuritis), unspecific diagnoses (dizziness and other peripheral vertigos) and sociodemographic characteristics obtained from the SIDIAP (Information System for the Development of Primary Care Research) database for 545,938 patients in 2019 and 513,638 in 2022. RESULTS: In 2019, the mean age was 51.0 years; 51.3% were women, and 2.68% of patients received a new vertigo-related diagnosis (2.44% nonspecific, 0.28% specific). In 2022, after the intervention, this increased to 2.80% (2.59% nonspecific, 0.28% specific). The IG showed significantly greater use of specific diagnoses (0.30% vs. 0.25%, p = 0.003), particularly BPPV (0.27% vs. 0.23%, p = 0.005). Regression models confirmed higher odds of diagnosis in the IG for any vertigo code (OR = 1.061), specific diagnoses (OR = 2.280), especially BPPV (OR = 2.283). CONCLUSION: A structured training intervention significantly improved the diagnostic coding of vertigo in primary care, fostering more accurate and specific diagnoses. TRIAL REGISTRATION: NCT04929444. First Submitted: 07/06/2021.