Association between Pain, Catastrophic Thinking, and Health-related Quality of Life in Patients with Hand Fractures

ABSTRACT

Objectives : Few reports have investigated the relationship between pain, catastrophic thinking, and health-related quality of life (QOL) in patients with hand fractures. We investigated the correlation between scores of the pain Numeric Rating Scale (NRS) and the Pain Catastrophizing Scale (PCS; rumination, helplessness, and magnification), and between the scores of PCS and health-related QOL based on the Short Form 8 questionnaire (SF-8).

Methods : Thirty-seven patients with hand and finger fractures were treated in a public hospital (16 men, 21 women; mean age, 56.5 years) and were treated by an occupational therapist. The relations between NRS, PCS, and SF-8 scores were examined at 4 to 6 months post-treatment. The effects of hand pain on catastrophic thinking and on mental, psychological, and daily role-based factors were analyzed by correlation and partial correlation analyses.

Results: The mean NRS score was 2.13. The mean PCS subitem scores were: rumination, 6.00; helplessness, 1.97; and magnification, 2.18. There were significant positive correlations between the NRS and all PCS scores. Relations between the PCS scores and SF-8 subitem scores, excluding items that were not correlated with NRS in partial correlation analysis, indicated significant negative correlations between multiple PCS subitems and SF-8 subitem scores for role physical, bodily pain, vitality, mental health, and physical component summary.

Conclusions: Pain and catastrophic thinking were correlated with health-related QOL in patients with hand fractures. In addition to assessing hand pain, therapists should monitor the effects of mental and psychological factors and daily activities in this group of patients.

INTRODUCTION

Hand trauma has a significant effect on upper-limb function. For example, chronic wrist pain was reported in 32% of patients after surgery for distal radius fracture and was reported to cause severe dysfunction in the fingers.^1,2) Recently, chronic pain associated with musculoskeletal disorders has been explained by the fear-avoidance model, and it has been demonstrated that catastrophic thinking is involved in chronic pain.^3,4) According to Sullivan et al.,⁵⁾ catastrophic thinking is interpreted as “an exaggerated negative attitude toward pain stimuli.” Relationships between catastrophic thinking and chronic pain in the lumbar spine and knee joints have been confirmed,^6,7) and psychological factors are known to be involved in the persistent pain observed in patients after knee-replacement surgery. Catastrophic thinking has been reported to be the factor that most affects post-operative pain.⁸⁾ However, few reports have shown that catastrophic thinking is involved in chronic pain in the upper limbs, especially the hands (including the wrist joint).^9,10)

The purpose of this study was to investigate the relationship between pain and catastrophic thinking and the relationship between catastrophic thinking and health-related quality of life (QOL) in patients with hand fractures. The study also considered the needs for therapy for pain in these patients, including assessments of the influences of pain on mental and psychological factors and tasks of daily living.

MATERIALS AND METHODS

The subjects were patients with hand fractures who were aged 20 years or older and received occupational therapy at Japan Agricultural Cooperatives, Obihiro Kohsei Hospital. We excluded patients with cognitive, mental, or verbal dysfunction because of the difficulty in assessing them through questionnaires. Patients with severe complex hand injuries involving blood vessels and nerves, such as amputations, were also excluded. Cases with complex regional pain syndrome that met the standards of the Ministry of Health, Labor, and Welfare of Japan were not included. Before treatment, the investigator explained to each patient that their personal information would be protected and that the contents of the survey would be reported to an academic journal. Written consent was obtained from the patients. The survey was conducted in compliance with the Declaration of Helsinki. This study was approved by the Ethics Committee of the Graduate School of Rehabilitation Sciences of the university (approval number: 20R140131).

Patient Characteristics

Data were collected from 37 patients (Table 1) with hand and finger fractures [mean age, 56.5 years; standard deviation (SD), 13.1 years; range, 20–85 years]. This cohort included 16 men (mean age, 50.7 years; SD, 14.6 years; range, 20–70 years) and 21 women (mean age, 60.9 years; SD, 10.4 years; range, 37–85 years). The age difference between the male and female groups was statistically significant (P=0.02). Of the 37 injuries, 23 were to the dominant hand and 14 were to the non-dominant hand. There was no significant difference in the dominant hand between the male and female groups (P=0.87). The breakdown of trauma was as follows: distal radius fracture in 18 cases, phalange fracture in 15 cases, and carpal bone fracture in 1 case. Surgical treatment was performed in 33 cases and conservative treatment was used in 4 cases. Eight patients were employed in agriculture or fishing; 14 were engaged in industries relating to construction, food processing, transportation, electrical equipment, factories, cooking, decoration, hairdressing, or confectionery; 10 identified as police, teachers, clerks, nursery employees, or nurses; and 5 were unemployed.

Table 1.  Patient characteristics

Age (years)	Sex	Injured hand	Occupation	Fracture	Treatment
57	Male	NDH	School janitor	Scaphoid fracture	ORIF
52	Female	NDH	Childcare	Bony mallet finger	Conservative
34	Male	DH	Construction industry	Phalangeal fracture	ORIF
66	Female	NDH	Farmer	Phalangeal fracture	ORIF
30	Male	NDH	Food processing	Phalangeal fractures	ORIF
54	Male	NDH	Transportation industry	Phalangeal fractures	ORIF
63	Male	DH	Electrical equipment	Phalangeal fracture	Conservative
42	Male	DH	Farmer	Phalangeal fractures	ORIF
37	Female	DH	Nurse	Phalangeal fractures	Pinning
58	Male	DH	Police	Distal radius ulna fracture	ORIF TFCC
57	Female	NDH	Farmer	Distal radius fracture	ORIF
67	Female	DH	None	Distal radius fracture	ORIF
62	Male	DH	Teacher	Distal radius ulna fracture	ORIF
64	Female	DH	None	Distal radius fracture	ORIF
20	Male	NDH	Clerk	Phalangeal fracture	ORIF
62	Male	DH	Fisherman	Phalangeal fractures	ORIF
54	Female	NDH	Office worker	Distal radius fracture	ORIF
54	Female	DH	Food processing	Distal radius fracture	ORIF
68	Male	DH	Agriculture	Distal radius fracture	ORIF
60	Female	NDH	Confectionery	Distal radius fracture	ORIF
61	Female	DH	Clerk	Distal radius ulna fracture	ORIF
57	Female	DH	Office worker	Distal radius ulna fracture	ORIF
67	Female	NDH	Clerk	Distal radius fracture	ORIF
62	Male	NDH	Construction industry	Phalangeal fracture	ORIF
61	Female	NDH	Cook	Distal radius fracture	Conservative
70	Female	DH	None	Phalangeal fracture	ORIF
64	Female	DH	Farmer	Phalangeal fracture	ORIF
42	Female	B	Farmer	Distal radius fracture	ORIF
43	Male	NDH	Confectionery	Phalangeal fracture	Pinning
57	Female	DH	None	Phalangeal fracture	ORIF
85	Female	DH	None	Distal radius fracture	ORIF
67	Female	DH	Nursery	Distal radius fracture	ORIF
58	Male	DH	Farmer	Distal radius fracture	ORIF
75	Female	NDH	Hairdresser	Distal radius fracture	ORIF
64	Male	DH	Decorator	Phalangeal fractures	ORIF
63	Female	DH	Confectionery	Distal radius fracture	ORIF
35	Male	DH	Farmer	Distal radius fracture	Conservative

NDH, non-dominant hand; DH, dominant hand; B, bilateral; ORIF, open reduction and internal fixation; TFCC, triangular fibrocartilage complex repair.

Data Collection

Data relating to pain intensity, catastrophic thinking, and health-related QOL were collected between 4 and 6 months post-treatment using questionnaires, and the three items were analyzed using scores. Pain intensity was assessed using the Numerical Rating Scale (NRS),¹¹⁾ catastrophic thinking was evaluated by the Pain Catastrophizing Scale (PCS),^5,12) and health-related QOL was assessed through the SF-8 Health Survey (SF-8).¹³⁾

The PCS scores were divided into the components of rumination, helplessness, and magnification. The subitems on the SF-8 questionnaire were physical functioning (PF), role physical (RP), bodily pain (BP), general health (GH), vitality (VT), social functioning (SF), role emotional (RE), and mental health (MH). These subitems formed components of the physical component summary and mental component summary (MCS). The scores of each item were calculated.

Statistical analyses of age, gender, and dominant/non-dominant hand in relation to NRS and PCS were performed by the Shapiro-Wilk test and a t-test when normality was observed, or by the Mann-Whitney U test when normality was not observed. The chi-square test was also used for the analysis of gender and hand differences.

Correlations between NRS score and PCS subitems (rumination, helplessness, and magnification), between NRS scores and SF-8 subitems, and between PCS subitems and SF-8 subitems were assessed using a significance test with Pearson’s or Spearman’s correlation coefficient depending on the normality of the measured values (Tables 2, 3, 4, 5). Based on G*Power software (version 3.1.9.2, Heinrich Heine University Dusseldorf, Germany), the sample size necessary for determining the significance of the correlation coefficient was 29. Therefore, correlation analyses were not performed separately in the male and female groups because the number of cases in each group was small.

Table 2.  Correlation coefficients between NRS and PCS subitem

	NRS	Rumination	Helplessness	Magnification
NRS	1.000	0.730**(0.00)	0.514**(0.00)	0.603**(0.00)
Rumination		1.000	0.440**(0.00)	0.738**(0.00)
Helplessness			1.000	0.450**(0.00)
Magnification				1.000

P values given in parentheses; **P<0.01.

Table 3.  Correlation coefficients between NRS and SF-8 subitems with summary scores

SF-8 subitem	Correlation with NRS
Physical functioning	−0.241 (0.14)
Role physical	−0.594** (0.00)
Bodily pain	−0.686** (0.00)
General health	−0.476** (0.00)
Vitality	−0.458* (0.00)
Social functioning	−0.372* (0.02)
Role emotional	−0.492** (0.00)
Mental health	−0.443** (0.00)
Physical component summary	−0.553** (0.00)
Mental component summary	−0.303 (0.06)

P values given in parentheses; *P<0.05, **P<0.01.

The partial correlation between PCS subitems and SF-8 subitems was analyzed as follows. First, significant correlations between PCS subitems and SF-8 subitems were calculated (Table 4). Subsequently, SF-8 subitems that were not correlated with the NRS score were identified by partial correlation analysis using the NRS score as a limiting factor (Table 5). Correlations in which a significant effect of the NRS scores was observed were extracted by deleting the latter significant SF-8 subitem from the former significant item. R4.22 statistical software (Modified R Commander; http//personal.hs.hirosaki-u.ac.jp/~pteiki/) was used for these analyses. The significance level was 5% in all comparisons.

Table 4.  Correlation coefficients between PCS subitems and SF-8 subitems with summary scores

SF-8 subitem	PCS subitem
	Rumination	Helplessness	Magnification
Physical functioning	−0.225 (0.14)	−0.324* (0.04)	−0.068 (0.68)
Role physical	−0.584** (0.00)	−0.548** (0.00)	−0.517** (0.00)
Bodily pain	−0.467** (0.00)	−0.444** (0.00)	−0.395* (0.01)
General health	−0.649** (0.00)	−0.682** (0.00)	−0.593** (0.00)
Vitality	−0.409* (0.011)	−0.463** (0.00)	−0.358* (0.02)
Social functioning	0.282 (0.08)	−0.305* (0.03)	−0.009 (0.56)
Role emotional	−0.479** (0.00)	−0.450** (0.00)	−0.262 (0.11)
Mental health	−0.519** (0.00)	−0.256 (0.12)	−0.351* (0.03)
Physical component summary	−0.497** (0.00)	−0.577** (0.00)	−0.424** (0.00)
Mental component summary	−0.374* (0.02)	−0.292 (0.07)	−0.182 (0.28)

P values given in parentheses; *P<0.05, **P<0.01.

Table 5.  Correlation coefficients between PCS subitems and SF-8 subitems with summary scores by partial correlation analysis using NRS as a limiting factor

SF-8 subitem	PCS subitem
	Rumination	Helplessness	Magnification
Physical functioning	−0.060 (0.72)	−0.176 (0.30)	0.094 (0.58)
Role physical	−0.264 (0.11)	−0.280 (0.09)	−0.094 (0.58)
Bodily pain	0.049 (0.77)	0.059 (0.79)	0.065 (0.70)
General health	−0.405* (0.01)	−0.543** (0.00)	−0.394* (0.01)
Vitality	−0.232 (0.17)	−0.403* (0.00)	−0.169 (0.32)
Social functioning	−0.082 (0.63)	−0.109 (0.52)	−0.175 (0.30)
Role emotional	−0.258 (0.12)	−0.332* (0.04)	0.017 (0.92)
Mental health	−0.26 (0.12)	0.001 (0.92)	−0.21 (0.21)
Physical component summary	−0.12 (0.48)	−0.275 (0.10)	−0.1 (0.55)
Mental component summary	−0.21 (0.21)	−0.17 (0.32)	−0.054 (0.75)

P values given in parentheses; *P<0.05, **P<0.01.

RESULTS

Gender Differences in NRS and PCS Scores and Dominant and Non-dominant Hands

The difference in NRS between the male and female groups was not significant (P=0.96). Similarly, there was no significant difference between the genders for the PCS subitems of rumination, helplessness, and magnification (P=0.98, P=0.31, and P=0.07, respectively). The difference in NRS score between the dominant and non-dominant hands was not significant (P=0.53), and there was no significant difference between the dominant and non-dominant hand for the PCS subitems of rumination, helplessness, and magnification (P=0.87, P=0.80, and P=0.50).

Correlation between NRS Score and PCS Subitem Scores

The mean NRS score was 2.13 (range, 0–6). The mean scores for the PCS subitems were: rumination, 6.00 (range, 0–15); magnification, 2.18 (range, 0–7); and helplessness, 1.97 (range, 0–10) (Fig. 1). The NRS and PCS subitem scores were significantly positively correlated, with correlation coefficients of 0.730 for rumination, 0.514 for helplessness, and 0.603 for magnification (all P<0.01) (Table 2).

Fig. 1.

Scores on the NRS and PCS (magnification, rumination, and helplessness). Mean scores are given on the figure.

Correlation between NRS Score and SF-8 Subitem Scores

With the exceptions of PF and MCS, significant negative correlations were detected between the NRS score and the SF-8 subitem scores. The analysis of the correlations between NRS scores and SF-8 subitem scores with the PCS score as a limiting factor showed that RP, BP, GH, VT, SF, RE, MH, and physical component summary score exhibited significant negative correlations (Table 3).

Correlation between PCS Score and SF-8 Subitem Scores

The SF-8 subitem scores with a mean deviation score of less than 50% of the national standard included BP, RP, and physical component summary (Fig. 2). Subitems with a mean deviation score greater than 51% of the national standard included GH, VT, MH, and MCS.

Fig. 2.

Deviation values of SF-8 subitems. The deviation value of each SF-8 subitem score from the national standard of 50% is shown. PCS, physical component summary.

Before subtraction of SF-8 subitem and summary scores that did not correlate with the effect of NRS score, all correlations between PCS subitems and SF-8 subitems and summary scores were examined. The SF-8 subitems and summary scores that were correlated significantly with the three PCS subitems were RP, BP, GH, VT, and physical component summary. The SF-8 subitems that correlated significantly with two PCS subitems were RW and MH, whereas PF, SF, and MCS correlated with one PCS subitem (P<0.05). All SF-8 subitems correlated with at least one PCS subitem (Table 4, Fig. 3a).

Fig. 3.

Correlation charts of the relationship among the scores for NRS, PCS subitems, and SF-8 subitems. (a) With or without influence of the effect of the NRS score. (b) Using NRS as a limiting factor. (c) With subtraction of SF-8 subitems without the influence of NRS score. Each line indicates a significant relationship between connected scales. The deviation values of SF-8 subitem scores are given in parentheses.

SF-8 subitems that were not correlated with the NRS score were then identified by partial correlation analysis using the NRS score as a limiting factor (Table 5, Fig. 3b). The SF-8 subitem and summary scores that were subtracted by deleting results obtained by partial correlation analysis are shown in Fig. 3c. The SF-8 subitems that were significantly correlated with the three PCS subitems were RP, BP, and physical component summary. SF-8 subitems VT and MH each correlated with two PCS subitems, whereas PF, SF, RE, and MCS each correlated with one PCS subitem (P<0.05) (Fig. 3c).

The SF-8 subitems RP, BP, VT, RE, and MH and the physical component summary score were correlated with the rumination score; PF, RP, BP, SF, physical component summary score, and MCS were correlated with the helplessness score; and RP, BP, VT, MH, and physical component summary score were correlated with the magnification score (Fig. 3c).

DISCUSSION

Subject Characteristics

The mean age of the subjects enrolled in this study was 56.5 (13.1) years. Of the 37 subjects, 32 were employed and were able to make outpatient visits while working, suggesting that they were highly active. The female subjects were older than the male subjects, possibly because of a large number of distal radius fractures that were attributed to osteoporosis (15 cases out of 21, Table 1).

There was no significant difference in PCS scores between male and female subjects or between dominant and non-dominant hands. According to a previous study, total PCS score and its component scores of helplessness and rumination tended to be higher in women than in men for healthy adults.¹²⁾ However, the present study found no gender differences in PCS scores. The mean age of the female subjects enrolled in this study was around 61 years, which is above the parenting age and may suggest lower levels of stress in the lives of these women. Although it is expected that a dominant-hand injury would be more disabling for activities of daily living than a non-dominant-hand injury, there was no difference in PCS scores regarding this parameter, indicating that catastrophic thinking occurred regardless of the injured side.

Relationship between NRS Score and PCS Subitems

Significant positive correlations were observed between the NRS score and all PCS subitems. Similar to previous studies that reported catastrophic thinking was associated with chronic pain in the lumbar spine and knee joints,^6,7) our results suggest that catastrophic thinking is also associated with pain in patients with hand fractures.^10,13)

Correlation between NRS Score and SF-8 Subitem Scores

Significant negative correlations were observed between the NRS score and the majority of the SF-8 subitem scores, indicating a significant negative correlation between pain and QOL. PF and MCS were the SF-8 subitems that were presumed to have no involvement in hand and finger pain.

Relationships between PCS Subitem Scores and SF-8 Subitem and Summary Scores

To accurately evaluate the relationship between PCS items and SF-8 subitem and summary scores, partial correlation analysis was performed to subtract the SF-8 subitem scores that have no influence on NRS scores (Fig. 3c). As a result, RP, BP, VT, MH, and physical component summary showed significant correlation with two or more of the PCS subitems. These data suggest that catastrophic thinking is expressed in social roles that require hand function, and that hand pain impairs the perception of physical health. Through catastrophic thinking, it is predicted that hand and finger pain may be involved in daily activity and physical and mental health related to the daily use of the upper extremities.

In contrast, GH had no correlation with any of the PCS subitems, whereas PF, SF, RE, and MCS were correlated with only one of the PCS subitems. It is presumed that in the absence of trauma to the lower extremities, the mobility of patients is preserved, thereby allowing participation in social activities and daily tasks that do not require use of the hands. Such scenarios do not affect healthy mental activity.

Correlation between each PCS Subitem and SF-8 Subitem and Summary Scores

Significant negative correlations with rumination were observed for RP, BP, VT, RE, MH, and physical component summary, suggesting that repeatedly thinking about hand pain and function makes the patients aware of their physical disability during work and daily activities (Fig. 3c). This leads to a perception of their own health as being poor and may trigger feelings of depression.

Significant negative correlations were observed between helplessness and PF, RP, BP, and physical component summary. These results suggested that the participants perceived physical and mental disability at work and during daily activities by thinking that they were helpless about hand pain, and that pain prevented them from working.

Significant negative correlations were observed between magnification and RP, BP, VT, MH, and physical component summary. These results suggest that excessive hand pain and functional disability render patients aware of their physical disability at work and during daily activities, thus triggering feelings of depression.

Recent Studies

There are two previous studies of catastrophic thinking after distal radius fractures. The study of 96 distal radius fracture cases by Teunis et al.⁹⁾ demonstrated that age, years of education, and catastrophic thinking (PCS total score) at 8 weeks after injury were related to reduced finger range of motion. They concluded that a maladaptive coping response to pain (catastrophic thinking) leads to stiff fingers. Surgeons and therapists should acknowledge the counter-perceptive aspects of recovery and help patients change their attitudes so that they are motivated to use their sore arms and perform uncomfortable stretching exercises. Another study of 216 distal radius fracture cases by Goudie et al.¹⁰⁾ reported that by using psychological measures (Hospital Anxiety and Depression Score, PCS, and Disabilities of the Arm, Shoulder, and Hand Questionnaire), the associations between depressive symptoms, illness perceptions, and outcomes of therapy were significant. A higher pain score at 9 months was associated with an increased number of medical co-morbidities. They noted that psychological factors are potentially modifiable after injury.

Rehabilitation in Patients with Hand Fractures

Many of the subjects enrolled in this study were employed and underwent outpatient rehabilitation while working. It was found that hand pain and catastrophic thinking after fracture were correlated with health-related QOL. Hand dysfunction may impair mental health, especially when the patients engage in social roles that require hand function. During therapy, the therapist informs the patient about the nature of the pain, provides a prognosis regarding functional recovery, and makes the patient aware of the prospect of reintegrating into society through normal work. It is important for the therapist to encourage the patient to break free from catastrophic thinking and to continue to play a social role by implementing initiatives to improve health-related QOL.

It is assumed that catastrophic thinking is stronger when the injury affects the dominant hand because the dominant hand is used more frequently at work and in daily life. However, the results of this study showed no significant difference in the occurrence of catastrophic thinking between patients with dominant-hand injuries and those with non-dominant-hand injuries.

There were multiple significant negative correlations between catastrophic thinking and health-related QOL in patients with hand fractures. Therefore, it is possible that pain and catastrophizing affect QOL. Hand pain is not only a perceptual aspect; rather, it also changes with cognition (such as thoughts and understanding of the environment) and emotions (such as anxiety and fear), thereby affecting behavior and life. The treating therapist should assess not only hand function but also catastrophic thinking in each patient. For employed patients in particular, it is important to assess hand pain and the level of difficulty in performing manual work during daily tasks and to implement initiatives to improve health-related QOL.

Clinical Approach to Hand Fractures as Occupational Therapists

The results of rehabilitation intervention using the Canadian Work Performance Model have been reported for patients with catastrophic thinking.^13,14) The intervention focused on the tasks that the patient needed to perform, and the sense of helplessness was reported to have improved.¹³⁾ However, a different intervention is necessary for the other two components of PCS (rumination and magnification).

For rumination, interventions that suppress repeated reminders of pain may be effective. Activities that allow the patient to forget pain, and interventions that elicit positive emotions such as enjoyment and happiness are considered to be effective.

For magnification, interventions to modify excessive magnification of pain are considered effective. For this purpose, patients should be educated to accurately recognize the pathophysiology of the injury or disability. Theoretical thinking interventions that can predict the course of recovery are also considered effective.

Limitations of this Study

A limitation of this study was that most of the subjects were employed; therefore, it is unclear whether similar results would be obtained in younger or older adults. Moreover, hand dysfunction was not investigated in this study, and the relationship between hand function and catastrophic thinking in the context of the performance of social roles was not assessed. The second important limitation of this study was that a significant correlation with the occurrence of the disease is not enough to identify the direct causal relationship between catastrophic thinking and hand fractures. In addition, the number of subjects enrolled in this study was small; therefore, there may be limitations in the results obtained through statistical analysis. Future studies should analyze an increased number of cases and examine in detail the PCS factors that affect hand function and QOL decline.

CONCLUSION

This study investigated the association between pain and catastrophic thinking and that between catastrophic thinking and health-related QOL in 37 patients with hand fractures. Scores of pain intensity and catastrophic thinking were significantly positively correlated, and catastrophic thinking and health-related QOL were significantly negatively correlated. In addition to the assessment of hand function, therapists should also assess these patients for pain and the contributing effects of pain on daily activities and mental and psychological factors.

ACKNOWLEDGMENTS

The authors acknowledge the assistance of Tatsuhiro Kamata, OT, PhD, for preparation of the study design, and Hirofumi Matsuoka, MD, PhD, for statistical analysis.

CONFLICTS OF INTEREST

The authors declare no conflict of interest.

REFERENCES

• 1.  Nakamura M, Toyama Y, Nishiwaki Y, Ushida T: Prevalence and characteristics of chronic musculoskeletal pain in Japan. J Orthop Sci 2011;16:424–432. PMID:21678085, DOI:10.1007/s00776-011-0102-y
• 2.  Jellad A, Salah S, Ben Salah Frih Z: Complex regional pain syndrome type I: incidence and risk factors in patients with fracture of the distal radius. Arch Phys Med Rehabil 2014;95:487–492. PMID:24080349, DOI:10.1016/j.apmr.2013.09.012
• 3.  Vlaeyen JW, Linton SJ: Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art. Pain 2000;85:317–332. PMID:10781906, DOI:10.1016/S0304-3959(99)00242-0
• 4.  Keogh E, Book K, Thomas J, Giddins G, Eccleston C: Predicting pain and disability in patients with hand fractures: comparing pain anxiety, anxiety sensitivity and pain catastrophizing. Eur J Pain 2010;14:446–451. PMID:19729326, DOI:10.1016/j.ejpain.2009.08.001
• 5.  Sullivan MJ, Bishop SR, Pivik J: The pain catastrophizing scale: development and validation. Psychol Assess 1995;7:524–532. DOI:10.1037/1040-3590.7.4.524
• 6.  Lewis GN, Rice DA, McNair PJ, Kluger M: Predictors of persistent pain after total knee arthroplasty: a systematic review and meta-analysis. Br J Anaesth 2015;114:551–561. PMID:25542191, DOI:10.1093/bja/aeu441
• 7.  Schiphorst Preuper HR, Geertzen JH, van Wijhe M, Boonstra AM, Molmans BH, Dijkstra PU, Reneman MF: Do analgesics improve functioning in patients with chronic low back pain? An explorative triple-blinded RCT. Eur Spine J 2014;23:800–806. PMID:24526247, DOI:10.1007/s00586-014-3229-7
• 8.  Vissers MM, Bussmann JB, Verhaar JA, Busschbach JJ, Bierma-Zeinstra SM, Reijman M: Psychological factors affecting the outcome of total hip and knee arthroplasty: a systematic review. Semin Arthritis Rheum 2012;41:576–588. PMID:22035624, DOI:10.1016/j.semarthrit.2011.07.003
• 9.  Teunis T, Bot AG, Thornton ER, Ring D: Catastrophic thinking is associated with finger stiffness after distal radius fracture surgery. J Orthop Trauma 2015;29:e414–e420. PMID:25866942, DOI:10.1097/BOT.0000000000000342
• 10.  Goudie ST, Broll R, Warwick C, Dixon D, Ring D, McQueen M: The association between psychological factors and outcomes after distal radius fracture. J Hand Surg Am 2022;47:190.e1–190.e10. PMID:34112544, DOI:10.1016/j.jhsa.2021.04.012
• 11.  Jensen MP, Turner JA, Romano JM: What is the maximum number of levels needed in pain intensity measurement? Pain 1994;58:387–392. PMID:7838588, DOI:10.1016/0304-3959(94)90133-3
• 12.  Matsuoka H, Sakano Y: Assessment of cognitive aspect of pain: development, reliability, and validation of Japanese Version of Pain Catastrophizing Scale. Jpn J Psychosom Med 2007;47:95–102. DOI:10.15064/jjpm.47.2_95
• 13.  Tokuda Y, Okubo T, Ohde S, Jacobs J, Takahashi O, Omata F, Yanai H, Hinohara S, Fukui T: Assessing items on the SF-8 Japanese version for health-related quality of life: a psychometric analysis based on the nominal categories model of item response theory. Value Health 2009;12:568–573. PMID:18783391, DOI:10.1111/j.1524-4733.2008.00449.x
• 14.  Carpenter L, Baker GA, Tyldesley B: The use of the Canadian Occupational Performance Measure as an outcome of a pain management program. Can J Occup Ther 2001;68:16–22. PMID:11233684, DOI:10.1177/000841740106800102