Another strong predictor? Step counts
Figure 4 illustrates the predominantly negative linear relationship between wearable-measured step counts and mortality risk in UK Biobank male participants under 60, after controlling for traditional underwriting risk factors.
For example, individuals averaging ~5,000 steps per day had an approximately 1.5 times higher mortality risk compared to those with ~11,000 steps per day (median step count value in this age group). Conversely, individuals with ~15,000 steps per day had an approximately 30% lower mortality risk compared to the median.
While the overall pattern was similar in adults aged 60 and older, the relationship appeared to be stronger in younger participants (data not shown). This association was generally consistent across all data subsets (i.e., proxy for standard, rated, and chronic disease lives; data not shown).
Compared to published results from a recent meta-analysis,15 our models, fitted to the various insurable populations, largely suggest that step counts have a slightly weaker impact on mortality. However, this is not surprising and is likely due to our inclusion of additional underwriting-relevant risk factors, which slightly attenuates the observed relationships.
Nonetheless, this remains an insightful and original finding, as this data comes from the largest objectively measured physical activity study in the world, with over 100,000 participants wearing wrist-worn accelerometers over a period of one week for 24 hours per day.
Figure 5 below shows the predictive power of replacing each traditional underwriting risk factor in the base model (i.e., BMI, smoker status, systolic blood pressure, and total cholesterol) with step counts in UK Biobank male participants under 60.
For example, the model鈥檚 ability to predict mortality risk increased by over 1% once total cholesterol was replaced by step counts. Similar effects were observed for BMI and systolic blood pressure, suggesting that step count is a stronger predictor of mortality than BMI, systolic blood pressure, and total cholesterol in the UK Biobank cohort. Model accuracy decreased when smoker status was replaced with step counts 鈥 suggesting that smoker status is a more important predictor of mortality in the UK Biobank cohort. Findings were indistinguishable across the different subsets of the data (i.e., older lives as well as proxy for standard, rated, and chronic disease lives; data not shown).
Implications for insurers
The findings from our UK Biobank study, in partnership with the University of Leicester, have clearly demonstrated that:
- BMI, self-reported walking pace, and wearable-measured step counts are significant and powerful predictors of all-cause mortality 鈥 findings that are applicable to insurable lives
- Wearable-measured step counts, in particular, could replace most traditional underwriting risk factors without reducing risk differentiation and may even improve risk segmentation
BMI plays a fundamental part in underwriting life and health insurance, while metrics such as self-reported walking pace and step counts have yet to be fully integrated into underwriting practices. Our findings regarding low BMI values are especially thought-provoking. Still, even though some insurers may already be aware of this, further research is needed before recommending broader underwriting changes.
On the other hand, as the industry increasingly seeks new and alternative data sources for underwriting life and health insurance,16 these findings provide compelling evidence on how self-reported walking pace and step counts can effectively segment mortality risk and complement traditional underwriting risk factors. These insights not only advance public health understanding of biometrics, healthy living, and mortality risks but also offer (re)insurers opportunities to refine underwriting philosophies and enhance wellness strategies.
Conclusion
In this paper, we have presented robust evidence on the prognostic value of BMI, self-reported walking pace, and wearable-measured step counts; findings that are highly applicable to insured lives. As the industry鈥檚 interest in biometric data continues to grow, these insights have the potential to enhance underwriting and wellness strategies, while also helping applicants make informed decisions to improve their longevity.
Further insights from our ongoing research and collaboration with the University of Leicester are expected to be released later this year.
with the lead researchers of the joint 69色情片 and University of Leicester study of UK Biobank data to learn more about quantifying biometrics risk factors.