Title:
Pain, health related quality of life and healthcare resource utilization in Spain.

Abstract:
The aim of this paper is to consider the relationship between the experience of pain, health related quality of life (HRQoL) and healthcare resource utilization in Spain.
The analysis contrasts the contribution of pain severity and frequency of pain reported against respondents reporting no pain in the previous month. Data are from the 2010 National Health and Wellness Survey (NHWS) for Spain. Single equation generalized linear regression models are used to evaluate the association of pain with the physical and mental component scores of the SF-12 questionnaire as well as health utilities generated from the SF-6D. In addition, the role of pain is assessed in its association with self-reported healthcare provider visits, emergency room visits and hospitalizations in the previous 6 months.
The results indicate that the experience of pain, notably severe and frequent pain, is substantial and is significantly associated with the SF-12 physical component scores, health utilities and all aspects of healthcare resource utilization, which far outweighs the role of demographic and socioeconomic variables, health risk factors (in particular body mass index) and the presence of comorbidities. In the case of severe daily pain, the marginal contribution of the SF-12 physical component score is a deficit of -17.86 compared to those reporting no pain (population average score 46.49), while persons who are morbidly obese report a deficit of only -6.63 compared to those who are normal weight. The corresponding association with health utilities is equally dramatic with a severe daily pain deficit of -0.186 compared to those reporting no pain (average population utility 0.71). The impact of pain on healthcare resource utilization is marked. Severe daily pain increases traditional provider visits by 208.8%, emergency room visits by 373.0% and hospitalizations by 348.5%.
As an internet-based survey there is the possibility of bias towards those with internet access, although telephone sampling is used to supplement responses. Respondents are asked to describe their experience of pain; there is no independent check on the accuracy of responses. Finally, while certain acute pain categories are omitted, the study focuses on pain in the last month and not on pain chronicity.
The societal burden of severe and frequent pain in Spain is substantial. Although not reported on before, at a national level, the deficit impact of the experience of pain far outweighs the contribution of more traditional explanations of HRQoL deficits as well as being the primary factor associated with increased provider visits, emergency room visits and hospitalizations.