The average life expectancy for a woman in Japan is 87 years. Due to recent advances in testing for cervical cancer, there is an increase in life expectancy by 15 years. The healthcare utility value is 0.8. Which of the following can be calculated from the parameters given?

Correct Answer: C. QALY

QALY (Quality-Adjusted Life Year) is the only metric that can be directly calculated from the given parameters: baseline life expectancy (87 years), gain in life expectancy (15 years), and healthcare utility value (0.8). QALY combines quantity of life (years gained) with quality of life (utility value) using the formula: QALY = Years of life gained × Utility value. Here, QALY = 15 years × 0.8 = 12 QALYs. This represents the net health benefit gained from the cervical cancer screening intervention. QALYs are fundamental to health economic evaluations and cost-effectiveness analysis in India, where resource allocation decisions increasingly rely on such metrics. The utility value (0–1 scale, where 1 = perfect health) reflects the quality adjustment, making QALY the appropriate measure when both quantity and quality parameters are provided. Unlike other metrics, QALY explicitly incorporates the healthcare utility value given in the question, making it the only calculable outcome from these specific parameters.

Why the other options are wrong

A. HALE — HALE (Health-Adjusted Life Expectancy) measures expected life lived in full health at birth, requiring age-specific disability weights and population health surveys—data not provided. While it uses utility-like adjustments, HALE is a population-level indicator calculated from epidemiological data, not from individual intervention parameters like utility values. The question provides intervention-specific gains, not population baseline health status needed for HALE. B. DALY — DALY (Disability-Adjusted Life Year) measures disease burden as the sum of years lost due to premature mortality and years lived with disability. It requires incidence/prevalence data, disability weights for the specific disease, and mortality rates—none of which are provided. DALYs quantify disease burden, not intervention benefit; the question describes a gain, not a burden calculation. D. DFLE — DFLE (Disability-Free Life Expectancy) is a population-level measure of years expected to be lived without disability, derived from population surveys and disability prevalence data. It does not use individual utility values as adjustment factors. The question provides intervention-specific utility (0.8), which is not the epidemiological disability data required to calculate DFLE.

High-Yield Facts

Mnemonics

QALY = Q × Y Quality (utility 0–1) × Years gained = QALY. When both are given, calculate QALY. When only population health status is given, think HALE. When disease burden is asked, think DALY. DALY = Disease burden; QALY = Intervention gain DALY quantifies what we lose (premature death + disability). QALY quantifies what we gain (years × quality). This question gives a gain scenario → QALY.

NBE Trap

NBE pairs life expectancy gains with HALE to trap students who confuse population-level health status measures (HALE) with intervention-specific benefit metrics (QALY). The presence of a utility value is the discriminator—QALY alone uses it directly in calculation.

Clinical Pearl

In Indian public health decision-making, QALYs are increasingly used to justify screening programs (e.g., cervical cancer via HPV vaccination) by demonstrating cost per QALY gained. A utility value of 0.8 suggests the screening intervention preserves good quality of life, making it economically attractive for resource-limited settings like India.

_Reference: Park's Textbook of Preventive and Social Medicine, Ch. 3 (Health Indicators and Indices); WHO-CHOICE guidelines on cost-effectiveness thresholds_