Chronic Pain in Patients with Hemophilia: Influence of Kinesiophobia and Catastrophizing Thoughts

To the Editor, People with haemophilia (PWH) usually begin to suffer pain at a young age. Physical and psychological components can accentuate patients’ pain. Pain has been identified as the most challenging and prevalent symptom, affecting up to 80% of PWH, and is the leading cause of disability in these patients.1 Some factors such as cognitive and social behaviour contribute to the impact of pain and are associated with poor prognosis following the onset of musculoskeletal pain.1,2 There is a complex interaction of factors that influence pain perception, such as mood swings, emotional problems, hypervigilance, kinesiophobia, catastrophic thoughts and negative beliefs. Negative thoughts can affect the sensation of pain. As a result, pain can be interpreted as a threat, and an overreaction can be initiated in response to this threat.3 Kinesiophobia is defined as an excessive, irrational and debilitating fear to carry out a movement resulting from a feeling of vulnerability due to a painful injury and may be associated with pain and disability. Kinesiophobia alters how people move, causing adjustments in motor behaviour, which affects the performance of actions related to the management and control of pain.3 This study aimed to measure kinesiophobia and catastrophic thoughts in PWH and analyze their impact on clinical and functional parameters, especially in PWH with chronic pain. In this study, we enrolled patients diagnosed with haemophilia A or B aged over 12 years. The evaluationwas performed fromAugust 2018 to July 2019, during PWH routine consultation at the haemophilia unit of Hemocentro UNICAMP, Brazil. Patients were considered eligible for the study when they could perform all clinical and functional assessments and adequately respond to all applied questionnaires. This study was approved by the independent local ethics committee (CAAE: 79822817.5.0000.5404). Informed consentwas obtained from all patients and their legal guardians. Patients were evaluated according to clinical and treatment information, including annualised bleeding rate (ABR), time of last bleeding, physical activity frequency and the number of affected joints. To define the presence or absence of chronic pain, patients were asked based on the definition of the International Association for the Study of Pain (IASP),4 which determines ‘chronic pain’ as recurrent or persistent pain in the last 3 months. According to the patients’ answers, they were assigned as ‘group with chronic pain’ or ‘group without chronic pain’. All patients classified as chronic pain were further assessed using the validated Multidimensional Haemophilia Pain Questionnaire (MHPQ).5 None of the patients from the group with chronic pain showed unexpected results in the MHPQ assessment, suggesting nomisclassification. On the same day of the consultation, PWH was assessed for Haemophilia Joint Health Score (HJHS 2.1), Functional Independence Score in Haemophilia (FISH), Pressure Pain Threshold (PPT)6 by pressure algometer, Tampa Scale for Kinesiophobia (TSK) questionnaire, and the pain-related catastrophising thoughts scale. The PPT test assesses pressure pain levels and pressure-pain threshold in six predetermined measurement positions for knees, ankles and elbows. The point of stimulation on the knees was: the anteromedial part of the joint line next to the patellar tendon with knees at 90o of flexion; the ankle point was considered the middle of the joint line between the anterior tibial tendon and the long extensor tendon of the hallux, and the elbow point was considered the middle of the triangle made up of the radial head, radial humeral epicondyle and olecranon, with elbows bent.6 ThePPT results of the right and left sides of each jointwere combined (average of both sides) to generate overall values for knee, ankle and elbow, expressed in Newton (N). The TSK is a self-administered questionnaire composed of 17 parameters on pain and fear of movement. The total TKSscale score ranges from17 to68,where17denotes no kinesiophobia, 68 denotes severe kinesiophobia and a score > 37 indicates the presence of kinesiophobia.7 Pain-related catastrophising thought scale is a self-administered questionnaire with nine questions on catastrophic thoughts about pain.8 Categorical variables were presented as frequency counts and percentages and were compared with Fisher’s exact test. Continuous data were presented as median and range (minimum and maximum values). Comparison between groups was carried out with Wilcoxon paired test, and Spearman’s correlationwas used to assess the correlation between clinical parameters. All statistical analyseswere performedwith TheR Foundation for Statistical Computing Version 3.6.1 and the significance level of the statistical tests was 5% (p< .05). The study included 71 PWH (58 hemophilia A and 13 hemophilia B) with a median age of 33 years (range: 12–87 years). Sixty-one patients were on secondary or tertiary prophylaxis, while 10 were treated on demand. All patients were negative for inhibitors. Regarding chronic pain, 46 patients (64.8%) were placed in the chronic pain group, and 25 patients (35.2%)were allocated to thenon-chronic pain group. Patients with chronic pain were older (p = .014), with a higher frequency of severe haemophilia A or B when compared to the non-chronic pain