Preclinical episodes of orofacial pain symptoms and their association with health care behaviors in the OPPERA prospective cohort study

The course of preclinical pain symptoms sheds light on the etiology and prognosis of chronic pain. We aimed to quantify rates of developing initial- and recurrent-symptoms of painful temporomandibular disorder (TMD) and to evaluate associations with health behaviors. In the OPPERA prospective cohort study, 2,719 people aged 18-44 years with lifetime absence of TMD when enrolled completed 25,103 quarterly (three-monthly) questionnaires during amedian 2.3-year follow-up period. Questionnaires documented TMD symptom episodes, headache, other body pain, health care attendance and analgesic usage and. Kaplan-Meier methods for clustered data estimated symptom-free survival time. Multivariable models assessed demographic variation in TMD symptom rates and evaluated associations with healthcare and analgesic use. One third of people developed TMD symptoms and for one quarter of symptomatic episodes, pain intensity was severe. Initial TMD symptoms developed at anannual rate of 18.8 episodes per 100 people. The annual rate more than doubled for first-recurrence and doubled again for second-or-subsequent recurrence such that, one year after first recurrence, 71% of people experienced second recurrence. The overall rate increased with age and was greater in African-Americans and lower in Asians relative to Whites. The probability of TMD symptoms was strongly associated with concurrent episodes of headache and body pain and with past episodes of TMD symptoms. Episodes of TMD symptoms, headache and body pain were associated with increases of ~10% in probability of analgesic usage and healthcare attendance. Yet, even when TMD, headache and body pain occurred concurrently, 27% of people neither attended healthcare nor used analgesics