Table 3.

Subgroup analysis results.

Subgroup	Incremental cost ($)	Incremental QALYs	Incremental cost-effectiveness ratio (ICER)
Age group: <65 years	$1200	0.08	$15,000 per QALY gained
Age group: ≥65 years	$1800	0.12	$15,000 per QALY gained
Disease severity: Mild	$800	0.10	$8000 per QALY gained
Disease severity: Severe	$2400	0.09	$26,667 per QALY gained

Explanation:

In this hypothetical example, subgroup analyses have been performed based on age groups and disease severity:

Age groups: The analysis shows that for patients aged < 65 years and ≥ 65, both ACE inhibitors and ARBs have similar incremental cost-effectiveness ratios (ICERs), suggesting that age does not significantly impact the cost-effectiveness of these treatments.

Disease severity: However, when considering disease severity, the ICERs differ significantly between patients with mild and severe heart failure. ACE inhibitors are more cost-effective for patients with mild heart failure with a lower ICER. In contrast, for patients with severe heart failure, ARBs have a higher ICER, indicating reduced cost-effectiveness in this subgroup.

Interpretation:

These subgroup analyses suggest that variations in baseline characteristics, such as age and disease severity, can influence the cost-effectiveness of ACE inhibitors and ARBs differently. It highlights the importance of considering patient heterogeneity when making treatment decisions.

Decision-makers need to consider these differences in cost-effectiveness when tailoring treatment recommendations for specific patient groups. Subgroup analyses provide valuable insights into which subpopulations may benefit most from each intervention and can inform personalized treatment strategies.

QALY = quality-adjusted life year.