Short- and long-term efficacy of brief cognitive-behavioral therapy for patients with chronic temporomandibular disorder pain: A randomized, controlled trial

Abstract

We evaluated the short- and long-term efficacy of a brief cognitive-behavioral therapy (CBT) for chronic temporomandibular disorder (TMD) pain in a randomized controlled trial. TMD clinic patients were assigned randomly to four sessions of either CBT ( n = 79) or an education/attention control condition ( n = 79). Participants completed outcome (pain, activity interference, jaw function, and depression) and process (pain beliefs, catastrophizing, and coping) measures before randomization, and 3 (post-treatment), 6, and 12 months later. As compared with the control group, the CBT group showed significantly greater improvement across the follow-ups on each outcome, belief, and catastrophizing measure (intent-to-treat analyses). The CBT group also showed a greater increase in use of relaxation techniques to cope with pain, but not in use of other coping strategies assessed. On the primary outcome measure, activity interference, the proportion of patients who reported no interference at 12 months was nearly three times higher in the CBT group (35%) than in the control group (13%) ( P = 0.004). In addition, more CBT than control group patients had clinically meaningful improvement in pain intensity (50% versus 29% showed ⩾50% decrease, P = 0.01), masticatory jaw function ( P < 0.001), and depression ( P = 0.016) at 12 months (intent-to-treat analyses). The two groups improved equivalently on a measure of TMD knowledge. A brief CBT intervention improves one-year clinical outcomes of TMD clinic patients and these effects appear to result from specific ingredients of the CBT. Keywords Cognitive-behavioral therapy Temporomandibular disorders Chronic pain Brief psychotherapy Randomized controlled trial 1 Introduction Cognitive-behavioral therapies (CBT) aim to decrease maladaptive, and to increase adaptive, patient cognitions and behaviors. These treatments are effective for a variety of chronic pain problems ( Keefe and Caldwell, 1997; Morley et al., 1999; Astin et al., 2002; Eccleston et al., 2002; Weydert et al., 2003; Chen et al., 2004 ). CB therapies are time-limited; the median number of treatment hours was 16 in the randomized controlled trials (RCTs) of CBT for chronic pain included in a comprehensive review ( Morley et al., 1999 ). However, limitations in insurance coverage for psychological therapies and the fact that most psychotherapy clients attend fewer than six sessions ( Shapiro et al., 2003 ) create the need for effective very brief (six or fewer sessions) CBTs for chronic pain problems. We previously reported changes on electronic daily diary measures of outcome and therapy process variables over the course of treatment in an RCT of a very brief CBT for patients with chronic temporomandibular disorder (TMD) pain ( Turner et al., 2005 ). TMDs are a group of conditions that involve the temporomandibular joints (TMJ), masticatory muscles, and associated structures, and share the common symptoms of pain, restricted jaw function, and TMJ noises ( Dimitroulis, 1998 ). The etiology of the most common types of TMD is largely unknown ( Dimitroulis, 1998 ). TMDs are the most frequent facial pain problems ( Dworkin, 1995b ), with an estimated prevalence of 10–12% ( Von Korff et al., 1988; Dworkin et al., 1990a; LeResche, 1997 ). Patients with TMD pain are similar to patients with other chronic pain conditions (e.g., headache and back pain) in terms of pain intensity and associated behavioral and psychological dysfunction ( Dworkin, 1995a ), pain persistence and recurrence ( Dworkin et al., 1989 ), and refractoriness of pain to treatment ( Rudy and Turk, 1995 ). Suggesting the importance of psychosocial factors in TMD problems, individuals with TMD vary widely in levels of disability (e.g., pain interference with customary activities; difficulty with masticatory and non-masticatory jaw activities such as opening jaws to bite food, chewing, and kissing) and psychosocial dysfunction ( Butterworth and Deardorff, 1987; Rudy et al., 1989; Suvinen et al., 1997 ) but objective findings do not appear to underlie these differences ( Rudy et al., 1989; Dworkin, 1995a ), and changes over time in jaw function measures are not clearly related to course of pain ( Ohrbach and Dworkin, 1998 ). We now report, following the Consolidated Standards of Reporting Trials (CONSORT) guidelines ( Moher et al., 2001 ), the short- and long-term results of our RCT of CBT versus an education/attention control condition for chronic TMD pain as assessed by standard questionnaire measures of outcome and therapy process variables. We hypothesized that the CBT group would show greater short- and long-term improvement on each outcome (pain, activity interference, jaw functioning, and depression) and process (pain-related beliefs, catastrophizing, and coping) measure. We examined clinically important as well as statistically significant change on the outcome measures. The primary outcome was activity interference and the primary endpoint was one-year. 2 Methods 2.1 Setting and participants The study was approved by the University of Washington (UW) Institutional Review Board and all participants provided written informed consent. Study participants were recruited by research staff from patients seeking care at the UW Orofacial Pain Clinic between June 2001 and February 2004. Study inclusion criteria were: (1) age 18 years or older; (2) a Research Diagnostic Criteria/Temporomandibular Disorders (RDC/TMD) Axis I TMD diagnosis ( Dworkin and LeResche, 1992 ) made by an oral medicine specialist based on a structured RDC/TMD clinical examination; (3) residence within a 2-h drive of the TMD clinic; (4) facial pain for at least three months; (5) facial pain-related disability, as defined by a chronic pain grade ( Von Korff et al., 1992 ) of II high, III, or IV (see Section 2.3 for definitions); and (6) ability to communicate in English. Study exclusion criteria (assessed by the patient’s oral medicine specialist...