Question 1

How do I choose the correct WHO subregion for my patient?

Accepted Answer

The WHO classifies countries into 14 subregions based on mortality strata (A-E) and geography (AFR, AMR, EMR, EUR, SEAR, WPR). The 2022 update simplified to six regions. Use the lookup table provided in the WHO PEN protocol to identify your country's region.

Question 2

Does the non-lab version perform adequately compared to the lab version?

Accepted Answer

Yes — in settings where lab tests are unavailable, the non-lab version (using BMI instead of cholesterol) provides acceptable discrimination. The C-statistic difference is small (approximately 0.02–0.04 lower than the lab version).

Question 3

Can WHO/ISH charts guide antihypertensive therapy independently of BP threshold?

Accepted Answer

Yes — that is a core feature. In the WHO PEN model, a patient with BP 160/99 and >30% risk is started on pharmacotherapy immediately, while the same BP with <20% risk allows a trial of lifestyle modification. This 'absolute-risk-based' approach is more efficient than treating based on BP alone.