Table 3.

Age-stratified mortality risk and intervention efficiency in A-CKM.

Onset age	A-CKM mortality rate (/1000 PY)	Control mortality rate (/1000 PY)	Absolute risk difference (/1000 PY)	10-year NNT (95% CI)
<45 years	2.48	0.69	1.79	56 (40 – 85)
45–54 years	11.11	4.36	6.75	15 (12 – 20)
55–64 years	17.24	8.63	8.61	12 (9 – 16)
≥65 years	33.95	28.29	5.66	18 (15 – 22)

Mortality rates: Expressed per 1,000 person-years (PY); Number needed to treat (NNT) calculation: NNT = 1000/(absolute risk difference × 10), representing patients needing 10-year intervention to prevent one death; absolute risk difference (ARD)=95% confidence intervals (CIs): computed via Fieller’s theorem accounting for distribution properties of ratio metrics.