Validation of the european SCORE risk chart in the healthy middle-aged Japanese

•The high- and low-risk SCORE model generally overestimates cardiovascular deaths in the general Japanese population.•Discrimination and calibration of both SCORE models were poor in the Japanese population overall, particularly in men.•Discrimination and calibration of the low-risk SCORE model was reasonable in Japanese women.

Background and aimsThe European Society of Cardiology developed prediction models (SCORE) for low- and high-risk populations in the European countries. However, whether or not these models are valid in different ethnicities is unknown. We aimed to evaluate the performance of the low-risk SCORE model in the general Japanese population.MethodsHealthy middle-aged Japanese participating in the NIPPON DATA80 cohort had been observed. The predicted 10-year cardiovascular death risk was calculated using the low-risk SCORE model for the overall population as well as for each gender individually. The model performance of the low-risk SCORE model was evaluated with the Harrel's c-statistics for discrimination and the Grønnesby and Borgan goodness-of-fit test for calibration.ResultsA total of 4842 participants aged 40-64 years old and 47,606 person-years were evaluated in our study. 203 (4.19%) died within the ten-years of follow-up and 44 (0.91%) CV deaths were observed. The low-risk SCORE model in the overall population had reasonable discrimination (c statistics 0.72, 95% CI 0.71-0.73) but poor calibration (R2, 0.67, Chi-square value 6.15, p = 0.01). Discrimination was reasonable in both men (c statistics 0.71, 95% CI 0.69-0.73) and women (c statistics 0.71, 95% CI 0.70-0.73). However, calibration was poor in men (R2, 0.22, Chi-square value 0.749, p = 0.38) compared to women (R2, 0.96, Chi-square value 1.39, p = 0.24).ConclusionsAlthough the low-risk SCORE model performs reasonably well in women, the SCORE models generally overestimated the risk of cardiovascular death risk in the Japanese general population.