Health numeracy skills of medical students:cross-sectional and controlled before-and-after study

BACKGROUND: Although numeracy, defined as understanding and handling numbers, is an important skill for the medical profession, it is not clear whether it changes during graduate medical education and whether it can be improved by specific interventions. The objective of this study was to assess objective and subjective numeracy levels at different stages of medical education and explore whether a research methodology/statistics course improves numeracy levels in a longer period. METHODS: We performed cross-sectional and controlled before-and-after studies. First-year sociology students and first- to sixth-year medical students from the in the cross sectional study and two groups of first-year medical students in a controlled before-and-after study. The intervention was a course on biostatistics and research methodology using blended approach. Numeracy was measured using Subjective Numeracy Scale (Cronbach α = 0.70) and Numeracy Understanding in Medicine instrument (Cronbach α = 0.75). RESULTS: Whereas first-year medical students did not differ from first-year sociology students in objective numeracy, medicine students had higher results on subjective numeracy. Students from higher years of medical school had generally higher subjective and objective numeracy scores. In the controlled before-and-after study, the intervention group improved more in subjective numeracy (median difference on a 0–8 scale = 0.5, 95% CI 0.3 to 0.7 vs − 0.4, 95% CI − 0.4 to − 0.1, P < 0.001) but not in objective numeracy. CONCLUSIONS: Although the numeracy levels at the beginning of the medical school are within the range of non-medical population, both objective and subjective numeracy improve during the higher years of medical school. Curriculum during medical school may help in numeracy increase, while research methodology training may help to increase subjective but not objective numeracy skills.