Asthma Is Associated with Back Pain and Migraine—Results of Population-Based Case–Control Study

(1) Background: Worldwide, asthma, back pain, and migraine are major public health problems due to their high prevalence, effect on the quality of life, and huge economic costs. The association of asthma with an increased risk of these types of pain has been suggested; however, no conclusive results have been obtained to date. The aims of our study were (1) to describe and compare the prevalence of three types of pain localization, namely migraine or frequent headaches (MFH), chronic neck pain (CNP), and chronic low back pain (CLBP), in adults with and without asthma in Spain during the years 2014 and 2020 and (2) to identify which variables were associated with the presence of these types of pain in adults with asthma. (2) Methods: A cross-sectional study and a case–control study were conducted. The 2014 and 2020 European Health Interview Surveys for Spain were used as the data source. (3) Results: A total of 2463 individuals were interviewed and had self-reported asthma. In this group, the prevalence of pain was high, with CLBP (30.9%) being the most common, followed by CNP (26.7%) and MFH (13.3%). All types of pain remained stable from 2014 to 2020. In both surveys, the women with asthma reported a remarkably higher prevalence of all the types of pain analyzed than the men with asthma. After matching by age and sex, the prevalence of all pain types was significantly higher in the patients with asthma than in the matched individuals without asthma. Multivariable adjustment showed that asthma increased the likelihood of CNP by 1.45 times (OR 1.45; 95% CI 1.19–1.76), that of CLBP by 1.37 times (OR 1.37; 95% CI 1.11–1.64), and that of MFH by 1.19 times (OR 1.19; 95% CI 1.02–1.51). The three types of pain analyzed were associated with the female sex and worse self-rated health. (4) Conclusions: Among the men and women with asthma, the prevalence of all the pain types was high and remained stable over time. The prevalence was higher and the severity was greater among the women with asthma than among the men with asthma. The prevalence of any pain was significantly higher in people with asthma than in the sex–age-matched individuals without asthma. Multivariable analysis showed that the variables associated with the reporting of the three types of pain in people with asthma were female sex, worse self-reported health, and self-reported mental illness