JMIR Publications

ABSTRACT

Background:

Hypertension is a leading preventable cause of cardiovascular disease, yet a substantial proportion of adults remain undiagnosed, limiting opportunities for early intervention. A predictive model was commissioned by the NWL Integrated Care Board to identify undiagnosed hypertension. The model was developed using health records from the Whole Systems Integrated Care (WSIC) database.

Objective:

We aimed to independently evaluate the predictive performance of the model, how performance varied by demographics and its utility in practice.

Methods:

To evaluate the predictive model, we conducted a retrospective cohort study of 1,802,920 individuals aged 16 years or older, registered with a GP in NWL and with no prior diagnosis of hypertension from May 2023–May 2024. We assessed the model's predictions against recorded hypertension status using medical diagnoses and blood pressure records. Logistic regression models were used to assess the sensitivity and specificity of the model’s predictions by sociodemographic groups.

Results:

The model yielded an overall sensitivity of 62.7% and specificity of 60.7%. Positive predictive value ranged between 31.5%–42.9%, and negative predictive value ranged between 77.6%–84.9%. Sensitivity was higher in older adults, females, Black patients, and those in deprived areas; specificity was higher in younger adults, males, White patients, and less deprived areas. Predictions varied by age, with 96.2% of those aged 70–79 predicted to have hypertension while only 0.3% of those aged 16–39 were predicted to have the condition.

Conclusions:

Despite the model's more reliable predictions for those without hypertension, the positive predictive value was low, and a significant proportion of true cases remained undetected. Future improvements may require more comprehensive data, including lifestyle factors not currently documented reliably in medical records. These insights can guide the practical application of the model, inform enhancements, direct targeted screening initiatives and support cost-benefit analyses for broader implementation to improve hypertension management.