Cognitive Behavioral Factors and Central Sensitization in Chronic Shoulder Pain

Primary outcomes

1. Central sensitization inventory (CSI)

   Time frame: 10 min

   The CSI contains a "part A" of 25 statements related to current health symptoms, indicative of central sensitisation (scored on a 5-point Likert scale ranging from 0-4). A mean score of 40 is the cut off value for central sensitization (Neblett et al 2013). The CSI has proven psychometric strength (Mayer et al 2012; Neblett et al. 2018).

2. Oxford Shoulder Score (OSS)

   Time frame: 10 min

   The Oxford Shoulder Score (OSS) is a 12-item patient-reported outcomespecifically designed and developed for assessing the impact on patients' quality of life of degenerative conditions such as arthritis and rotator cuff problems. Substantial evidence from clinical studies shows that the PRO has high internal consistency and is a valid and reliable measure of patient well-being. The intraclass correlation has been calculated as 0.83 (Ekeberg,2008 ). In this study, • Self-report functional will be assessed with the Oxford Shoulder Score.

3. Tampa Scale for Kinesiophobia

   Time frame: 10 min

   To measure kinesiophobia, the Tampa Scale for Kinesiophobia was used. Patients have to score 17 opinions on a 4-point Likert scale (1 = highly disagree, 4 = highly agree). Scores ≥37/68 indicate kinesiophobia. This questionnaire has good internal consistency and test-retest reliability.

4. Hospital Anxiety and Depression Scale (HADS)

   Time frame: 10 min

   Hospital Anxiety and Depression Scale (HADS) is commonly used to determine the levels of anxiety and depression. The HADS is a fourteen item scale that generates ordinal data. Seven of the items relate to anxiety and seven relate to depression. A number of researchers have explored HADS data to establish the cut-off points for caseness of anxiety or depression. Bjelland et al (2002)[2] through a literature review of a large number of studies identified a cut-off point of 8/21 for anxiety or depression. For anxiety (HADS-A) this gave a specificity of 0.78 and a sensitivity of 0.9. For depression (HADS-D) this gave a specificity of 0.79 and a sensitivity of 0.83.

5. Pain Catastrophizing Scale

   Time frame: 10 min

   To measure the extent of pain catastrophizing, we will be used the Pain Catastrophizing Scale, which consists of 13 items exploring pain-related cognition, which the patient has to score on a 5-point Likert scale (0 = not at all, 4 = all the time). Scores ≥30/52 reveal a clinically relevant degree of catastrophizing. This questionnaire is found to have good internal consistency and test-retest reliability, as well as proven construct and criterion validity.

6. Brief Illness Perception Questionnaire

   Time frame: 3 min

   Patients' illness perceptions will be measured based on the Brief Illness Perception Questionnaire. The patient has to rate 8 statements on a 10-point scale (1-10). The higher the score, the greater is the extent to which the patient's illness perceptions are threatening him or her.

7. Arm Endurance Test

   Time frame: 5 min

   Pain behavior will be assessed using the arm Endurance Test. This test measured the time the patient could hold both arms horizontally out to the side describing small circles. The tester continued timing while the fingers remained above a line level with the elbow when the arm was dependent (Hardind et al. 1994).

8. Numeric Pain Rating Scale

   Time frame: 1 min

   The Numeric Pain Rating Scale (NPRS) is a unidimensional measure of pain intensity in adults. The most commonly used is the 11-item NPRS. The 11-point numeric scale ranges from '0' representing one pain extreme (e.g. "no pain") to '10' representing the other pain extreme (e.g. "pain as bad as you can imagine" or "worst pain imaginable").The NPRS is a valid and reliable scale to measure pain intensity. In this study, will rate current pain intensity and mean pain intensity durind the past 7 days.