Just one question: If one question works, why ask several?
- Correspondence to: Professor A Bowling Department of Primary Care and Population Sciences, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK;
- QoL, quality of life
- HRQoL, health related quality of life
- GHS, General Household Survey
- VAS, visual analogue scale
While shorter instruments are more limited than longer measures, they have obvious benefits for both research and policy in terms of reduced burden and costs, and ease of interpretation.
A frequently asked question by clinical investigators is why they should use a lengthy, multi-item measurement scale to assess patients’ perceptions of their health, or quality of life, when there is evidence that a measure containing a single, global question is likely to suffice. Researchers may not wish to use lengthy scales because their core questionnaires are already long, the patient group of interest is ill or frail, they wish to minimise the burden on the patient and on the research team, or they simply want a “snap shot” of a topic rather than comprehensive coverage. In such circumstances, single questions have the obvious advantage of brevity, of making fewer demands than multi-item measures on respondents and researchers. Single, global questions have long been used in population surveys to measure health status, quality of life (QoL), and health related quality of life (HRQoL). The two most popular single global health items are self rated health status and self reported limiting, longstanding illness.
SELF RATED HEALTH STATUS
The classic self rated health status item consists of asking respondents to rate their health as “excellent, good, fair, or poor”. Variations of this question have been used in surveys worldwide. Literature reviews on the conceptualisation and measurement of health published by Rand in the USA1,2 and an overview by Stewart and Ware3 reported citations of the self rated health item as early as early as the 1950s. For example, a version appeared in a US study of occupational retirement4 and in the US Federal Civil Defense Administration Survey, both in the 1950s.5 And a question asking people to rate their general health, followed …