Key finding
1-SD decrement in low-frequency HRV power associated with 1.70x greater all-cause mortality hazard (95% CI 1.37–2.09) over 4 years in an elderly community cohort
Evidence & causal status
Moderate
Associational; reflects autonomic dysfunction, prognostic value shown independent of traditional risk factors
Caveats & limitations
Reliability / bias notes: Older, smaller cohort (n=736, 74 deaths); short 2-hour ECG recording window; results in elderly may not generalize to younger adults
This describes a population-level association from published research. It is not a prediction about any one individual, and association is not the same as causation unless stated otherwise above.