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.