Chronic pain and health-related quality of life: a population-based study
Chronic pain, that is pain of greater than 3 months duration is a global public health problem. Previous studies have estimated that up to 43.5% of people experience some form of chronic pain, with 10% to 14% experiencing moderate to severe pain. Chronic pain is costly; annual costs have been estimated at up to 635 billion US dollars in the USA, and 200 billion Euros in Europe. The burden of chronic pain has been studied, typically through small-sized studies of individual conditions or pain locations, or by using data that have been aggregated and do not offer the detail that may be gained from a large study using individual participant data.
Our study will provide new and important knowledge about the burden of chronic pain at a population level. The new information will be useful to inform policy, decision making, and the evaluation of future interventions to improve the lives of those with chronic pain.
- For individuals with chronic pain (CP), how does their self-reported health-related quality of life (HRQoL) compare with those without pain, and how does it compare with population norms?
- How are social and demographic factors are associated with reduced quality of life in people with chronic pain?
- What are the annual QALY losses accounted for by chronic pain?
Using data from a population-based study of UK adults aged between 40 and 69 at recruitment (n~=500,000), with ~10-year follow-up (n~=138,000):
AIM1: to estimate the prevalence of chronic pain at baseline and at ~10-year follow-up, by pain site
AIM2: to compare the health-related quality of life (HRQoL) of participants reporting chronic pain with those who reported no pain, by pain site
AIM3: to compare the HRQoL of participants with chronic pain with age and sex-specific population norms, by pain site
AIM4: to identify social and demographic predictors of deviations from HRQoL norms for individuals with chronic pain, by pain site
AIM5: to quantify the annual QALY losses associated with chronic pain (not considering mortality)
REQUESTED EXTENDED SCOPE
We wish to expand the scope of our approved HRQoL and chronic pain project with the addition of complementary analyses to summarise the HRQoL of the general older adult population in England (i.e. not specifically focussed on people with chronic pain).
No large general population studies of HRQoL derived from EQ-5D-5L responses have been published for the English population, and there are no population norms.
The EQ-5D-5L data contained in the 2019 Pain Questionnaire responses offer an opportunity to present a contemporary view of the HRQoL of a large general sample (n~149,000 aged 49+ with complete EQ-5D-5L data) of the English population.
- For each EQ-5D-5L descriptive dimension (mobility, self-care, usual activities, pain/discomfort, anxiety/depression), to summarise the frequencies and proportions of participants by level of problem (none, slight, moderate, severe, extreme), age (45-54, 55-64, 65-74. 74+), and sex.
- For each EQ-5D-5L descriptive dimension, to estimate age and sex adjusted odds ratios (and 95% confidence intervals) of experiencing problems.
- To estimate age and sex adjusted health-utilities (index scores).
- Using weights from the EQ-5D-5L value set for England (Devlin, 2018), and
- By mapping to EQ-5D-3L (Hout, 2012) and using the 3L value set, per the NICE position statement on use of the EQ-5D-5L value set
- To explore the stability of the derived health utilities by indices of deprivation, ethnicity, and education.
STRENGTHS AND LIMITATIONS
While the UK Biobank contains a large number of participants, it may not be a representative sample of the entire population. However, much smaller published estimates of population norms are not necessarily unbiased, and where norms do not exist, norms from other counties are often appropriated and used.
Given that there are no published large-scale summary population level studies of HRQoL for people in England derived from the EQ-5D-5L there is value in this work. The results will be presented cautiously, not as population norms, but as summary data of a very large cohort. In doing so, we will provide new knowledge about the health-related quality of life for a large English cohort, and explore the effects of relevant socio-economic factors on the health utilities derived. These results will be useful to other UK Biobank researchers as a EQ-5D-5L reference, and to health research relating the English population more broadly.