The development of psychological changes ... - Regis University

4 downloads 840 Views 399KB Size Report
28, GHQ-28), fear of movement/re-injury (TAMPA Scale of Kinesphobia, TSK), acute ..... support this view, where TSK scores of the group with mild symptoms ...
Pain 106 (2003) 481–489 www.elsevier.com/locate/pain

The development of psychological changes following whiplash injury Michele Sterlinga,*, Justin Kenardyb, Gwendolen Julla, Bill Vicenzinoa a

The Whiplash Research Unit, Department of Physiotherapy, The University of Queensland, St Lucia, Brisbane, Qld 4072, Australia b Department of Psychology, The University of Queensland, Brisbane, Qld 4072, Australia Received 11 May 2003; received in revised form 19 August 2003; accepted 17 September 2003

Abstract Psychological distress is a feature of chronic whiplash-associated disorders, but little is known of psychological changes from soon after injury to either recovery or symptom persistence. This study prospectively measured psychological distress (General Health Questionnaire 28, GHQ-28), fear of movement/re-injury (TAMPA Scale of Kinesphobia, TSK), acute post-traumatic stress (Impact of Events Scale, IES) and general health and well being (Short Form 36, SF-36) in 76 whiplash subjects within 1 month of injury and then 2, 3 and 6 months postinjury. Subjects were classified at 6 months post-injury using scores on the Neck Disability Index: recovered (,8), mild pain and disability (10 – 28) or moderate/severe pain and disability (. 30). All whiplash groups demonstrated psychological distress (GHQ-28, SF-36) to some extent at 1 month post-injury. Scores of the recovered group and those with persistent mild symptoms returned to levels regarded as normal by 2 months post-injury, parallelling a decrease in reported pain and disability. Scores on both these tests remained above threshold levels in those with ongoing moderate/severe symptoms. The moderate/severe and mild groups showed elevated TSK scores at 1 month post-injury. TSK scores decreased by 2 months in the group with residual mild symptoms and by 6 months in those with persistent moderate/severe symptoms. Elevated IES scores, indicative of a moderate post-traumatic stress reaction, were unique to the group with moderate/severe symptoms. The results of this study demonstrated that all those experiencing whiplash injury display initial psychological distress that decreased in those whose symptoms subside. Whiplash participants who reported persistent moderate/severe symptoms at 6 months continue to be psychologically distressed and are also characterised by a moderate post-traumatic stress reaction. q 2003 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved. Keywords: Psychological distress; Whiplash-associated disorders; Post-traumatic stress

1. Introduction Whiplash-associated disorders (WAD) is a complex condition involving disturbances in motor function, nociceptive processing and psychological distress (Curatolo et al., 2001; Moog et al., 2002; Nederhand et al., 2002; Sterling et al., 2002). Whilst much of this evidence has been gained from investigation of those with chronic WAD, it is becoming apparent that some of these changes are present soon after injury and are likely to be important in the transition to either recovery or symptom persistence. Motor and sensory disturbances develop soon after injury and persist in those with poor recovery (Sterling et al., 2003a,b). Whilst psychological factors are believed to be important in the transition from acute to chronic spinal pain (Linton, 2000), this has not been well investigated in WAD. * Corresponding author. Tel.: þ 61-7-3365-4568; fax: þ61-7-3365-2775. E-mail address: [email protected] (M. Sterling).

Investigation of psychological factors to date suggests that the psychological distress seen later in the chronic stage of WAD is most likely a consequence of ongoing pain and disability (Gargan et al., 1997; Radanov et al., 1995). Gargan et al. (1997) showed normal levels of psychological distress within a week of injury that became elevated at 3 months post-injury in association with restricted neck movement. This view is supported by other prospective studies where delayed recovery following whiplash injury could not be predicted from psychological factors such as personality traits or self-rated well being but was related to injury severity (Borchgrevink et al., 1997; Radanov et al., 1995). A recent large crosssectional study showed an association between anxiety and depression with pain and disability in whiplash patients whose accidents occurred over 2 years previously but not in those with acute injury, suggesting that symptom persistence is the trigger for psychological distress (Wenzel et al., 2002).

0304-3959/$20.00 q 2003 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.pain.2003.09.013

482

M. Sterling et al. / Pain 106 (2003) 481–489

Despite these studies, the investigation of psychological factors in WAD is relatively sparse when compared to that of other musculoskeletal conditions. Psychological factors known to be important in the development of chronic low back pain such as beliefs about the fear of movement/re-injury are yet to be investigated in WAD (Vlaeyen and Linton, 2000), despite speculation that such beliefs play a role in the pain and disability seen in this condition (Nederhand et al., 2002). Furthermore whiplash injury differs from many other musculoskeletal pain syndromes in that a traumatic event (motor vehicle crash) precipitates its onset. This has led to some investigation of the role posttraumatic stress plays in the development of persistent symptoms. Drottning et al. (1995) showed that high levels of acute emotional distress within days of the accident were associated with ongoing symptoms at 4 weeks post-injury. The effect of post-traumatic stress on more long-term outcome is unknown. It is apparent that further investigation of psychological factors in WAD from the time of injury is required. Such investigation should include a variety of psychological measures such that a more comprehensive psychological profile of the continuum of WAD is realised. The aims of this study were twofold: to investigate the differences in psychological factors between those who recover and those who report persistent symptoms and to investigate the prospective longitudinal development of such changes following whiplash injury.

If the patient was agreeable, an appointment was made for them to attend the Research Unit to complete the questionnaires. At this appointment written informed consent was gained from each subject. Subjects were eligible if they met the Quebec Task Force (QTF) classification of WAD II or III (Spitzer et al., 1995). Subjects were excluded if they were WAD IV, experienced concussion, loss of consciousness or head injury as a result of the accident and if they reported a previous history of whiplash, neck pain, headaches or psychological disturbance that required treatment. Ethical clearance for this study was granted from the Medical Research Ethics Committee of The University of Queensland. 2.3. Self-reported pain and disability Self-reported pain and disability was measured using the Neck Disability Index (NDI). The NDI consists of 10 items addressing functional activities such as personal care, lifting, reading, work, driving, sleeping and recreational activities as well as pain intensity, concentration and headache (Vernon and Mior, 1991). There are six potential responses for each item ranging from no disability (0) to total disability (10). The overall score (out of 100) is calculated by totalling the responses of each individual item and multiplying by two. A higher score indicates greater pain and disability (Vernon and Mior, 1991). The NDI has been shown to be reliable and valid (Pietrobon et al., 2002). 2.4. Psychological questionnaires

2. Methods 2.1. Study design A prospective longitudinal design was used to study persons who sustained a whiplash injury from within 1 month of injury to 6 months post-injury. They were assessed on four occasions—within 1 month of injury, 2, 3 and 6 months post-injury. 2.2. Subjects Eighty volunteers (24 males, 56 females, mean age 36.27 ^ 12.69 years) reporting neck pain as a result of a motor vehicle crash participated in the study. The whiplash subjects were recruited via hospital accident and emergency departments (13%), primary care practices (medical and physiotherapy) (53%) and from advertisement within radio and print media (34%). Physiotherapy and medical practitioners in community practices and the hospital department approached all patients who presented with an acute whiplash injury and sought approval for a member of the research team to contact them further by telephone. A research assistant contacted these patients and explained their involvement in the study. With respect to media recruitment, the subject made the initial telephone contact.

Four psychological tests were chosen for this study in order to gain an overview of the psychological distress experienced by the subjects in addition to beliefs about the fear of movement and re-injury and acute post-traumatic stress reaction. The General Health Questionnaire 28 (GHQ-28) is a 28-item measure of emotional distress in medical settings, which is divided into four subscales: somatic symptoms (items 1 – 7); anxiety/insomnia (items 8 – 14); social dysfunction (items 15 – 21); and severe depression (items 22– 28) (Goldberg, 1978). The total score can be used as a measure of psychological distress. The GHQ-28 has been used in previous research of WAD (Gargan et al., 1997). The TAMPA Scale of Kinesphobia (TSK) is a 17-item questionnaire that measures the fear of re-injury due to movement (Crombez et al., 1999; Kori et al., 1990). Each item uses a Likert scale with scoring alternatives ranging from ‘strongly agree’ to ‘strongly disagree’. The TSK has been shown to be both reliable and valid (Vlaeyen and Linton, 2000). The Impact of Events Scale (IES) is a 15-item questionnaire that measures current stress related to a specific life event (Horowitz et al., 1979). Two response sets are reported to be associated with psychological reactions to stress—avoidance and intrusion (Drottning et al., 1995).

M. Sterling et al. / Pain 106 (2003) 481–489

Intrusion is characterised by unbidden thoughts and images, troubled dreams, strong feelings about the incident and repetitive behaviour, whereas avoidance responses include ideational constriction, denial of the consequences of the event, behavioural inhibition and awareness of emotional numbness (Drottning et al., 1995). The IES has seven items that cover intrusive symptoms. Five of these items reflect acute intrusive symptoms whilst awake and two reflect intrusion during sleep (nightmare, insomnia). The avoidance subscale has eight items. The IES has been validated in studies of the acute emotional response to trauma (Karlehagen et al., 1993) and has shown good reliability and sensitivity (Horowitz et al., 1979). The Short Form 36 (SF-36) was used as a measure of general health and well being (Ware et al., 1993). The SF-36 provides an indicator across eight dimensions of health and well being: physical functioning, role limitations due to physical problems, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems and mental health as well as a separate single item dimension called health transition (Ware et al., 1993). 2.5. Procedure The subjects attended the research unit at each of the four assessment points and completed all questionnaires. 2.6. Statistical analysis The whiplash subjects were classified into one of three groups based on results of the NDI at 6 months post-injury. The groups were recovered (, 8 NDI), mild pain and disability (10 – 28 NDI) and moderate/severe pain and disability (. 30 NDI) (Vernon, 1996). We have used this classification previously in the investigation of WAD (Sterling et al., 2003a,b). A repeated measures mixed model analysis of variance with a between-subjects factor of Group (three levels: recovered, mild, moderate/severe) and a within-subjects factor of Time (four levels: , 1, 2, 3 and 6 months postinjury) was performed. Age and gender were used as covariates in this analysis. Differences between the groups were analysed with a priori contrasts (i.e. pairwise comparisons). Significance was set at P , 0:01: The relationship between self-reported pain and disability (NDI) and psychological measures of GHQ-28 and TSK were examined at entry to and exit from the study using Pearson product – moment correlations.

483

Fig. 1. Mean (SEM) NDI scores for three whiplash groups (recovered, mild pain and disability, moderate/severe pain and disability) at each assessment point (,1, 2, 3 and 6 months post-injury).

The reasons given for withdrawal included relocation to another city (two subjects), a head injury several weeks following the whiplash injury (one subject) and no reason given (one subject). The remaining 76 subjects formed the 6-month classification. The NDI of the recovered group was 2.9 ^ 2.9 (mean ^ SD), the mild group 16.3 ^ 5.6 and the moderate/severe group 42.8 ^ 12.2. NDI scores of the three groups significantly improved from entry to exit from the study ðP , 0:01Þ (Fig. 1). Thirty-eight percent of the whiplash subjects reported recovery by 6 months postinjury, 39.6% reported persistent mild pain and disability and 22.4% persistent moderate/severe pain and disability based on NDI scores at 6 months. Age and gender distribution of the four groups is illustrated in Table 1. There was an uneven distribution of males and females and differences in ages between the groups approached significance ðP ¼ 0:03Þ: As a consequence, age and gender were included as covariates in the initial analysis. NDI and VAS scores of pain intensity at each time point are shown in Table 2. At entry into the study, headaches, dizziness, paraesthesia, arm, thoracic and lumbar spine pain were reported to varying extents in all three groups albeit to a greater extent in those with persistent moderate/severe symptoms. Table 3 details the extent of reported symptoms at entry into and exit from the study in each group. This study did not aim to investigate the effect of treatment and as such subjects were free to pursue any form of treatment. The types and numbers of treatments were documented at each assessment point. Treatments received (including medication) were not different between the three whiplash groups (Table 4). Ninety-seven percent of the cohort returned to work by 3 months post-accident. The time since injury ranged from 10 days to 4 weeks (mean 3.17 weeks). 3.2. GHQ-28

3. Results 3.1. Subject classification at 6 months post-injury Of the 80 subjects who entered the study, four withdrew during the study period, all after the initial assessment point.

The marginal means (^ SEM) of the three groups for the four sub-components and the total score of the GHQ-28 are presented in Table 5 and Fig. 2. There was a significant effect for Group ðP , 0:001Þ for the four sub-components of the GHQ-28 as well as the total

484

M. Sterling et al. / Pain 106 (2003) 481–489

Table 1 The age, gender, recruitment source and classification of subject groups at 6 months according to Vernon’s (1996) categories of NDI scores (Vernon, 1996) Group

Recovered Mild pain and disability Moderate/severe pain and disability

N

29 30 17

Age (years) (mean ^ SD)

29.3 ^ 11.72 34.3 ^ 12.5 43.7 ^ 14.5

Gender% female

50 77 94

Source

NDI classification

AE ðNÞ

PC ðNÞ

Ad ðNÞ

3 4 3

14 12 14

8 10 8

,8 10–28 .30

AE, accident and emergency; PC, primary care practice; Ad, advertisement.

Table 2 Mean (SD) NDI and VAS scores for each whiplash group (recovered, mild pain and disability and moderate pain and disability) at each time point ,1 month

2 months

3 months

6 months

NDI Recovered Mild pain and disability Moderate/severe pain and disability

19.14 (12.7) 36.1 (19.4) 55.6 (13.4)

8 (8.2) 25.6 (10.8) 49.1 (15.1)

5.4 (6.8) 21.45 (12.6) 47.4 (15.4)

2.9 (2.9) 16.3 (5.6) 42.8 (12.2)

VAS Recovered Mild pain and disability Moderate/severe pain and disability

2.3 (0.9) 3.2 (1.2) 3.2 (1.3)

1.5 (0.8) 2.6 (0.9) 3.8 (1.3)

0.6 (0.1) 0.9 (0.2) 3.3 (1.3)

0.3 (0.1) 2.0 (0.7) 3.4 (1.0)

score. There was a significant interaction between Group and Time for the total score and the somatic symptoms, anxiety/insomnia and social dysfunction sub-components ðP , 0:001Þ but not for the depression component of the test ðP ¼ 0:31Þ: At entry into the study (, 1 month post-injury), the groups with persistent mild or moderate/severe symptoms showed GHQ-28 total scores of 31.94 ^ 2.2 and 42.38 ^ 3.1 (mean ^ SEM), respectively, which were above the threshold of 23/24. Both these groups’ scores were significantly higher than scores of the group that recovered by 6 months (19.57 ^ 2.3) ðP , 0:01Þ: All three groups improved over time and by 2 months post-injury, total scores of the mild group (20.76 ^ 2.3) had dropped to below the threshold. Although those with moderate/severe symptoms also showed significant improvement from 1 to 2 months post-injury ðP ¼ 0:002Þ; their scores then plateaued and remained above the threshold at 6 months (33.69 ^ 3). With respect to the sub-components of the GHQ-28, the moderate/severe group showed higher scores than the other two groups on the somatic symptoms, anxiety/insomnia and depression components at entry into the study ðP , 0:01Þ; with scores of the mild group also being significantly greater than those of the recovered group for these sub-components ðP , 0:01Þ: Scores of the social functioning component were significantly higher in both the mild and moderate/ severe groups when compared to the recovered group ðP , 0:01Þ with no difference between the former two groups ðP ¼ 0:06Þ: All three groups showed improvement over time on the social functioning component of

the GHQ-28, but by 6 months the moderate/severe groups’ social functioning scores remained significantly higher than the other two groups ðP , 0:01Þ: The recovered and mild groups improved over time on the somatic symptoms and anxiety/insomnia components of the test ðP , 0:01Þ; with scores of the moderate/severe group remaining unchanged for these components ðP . 0:052Þ: Depression scores remained unchanged over time in all three groups ðP . 0:13Þ: There was no effect of age or gender on the total score of the GHQ-28 or any of the four sub-components ðP . 0:05Þ: At both entry into and exit from the study, there was a significant correlation between NDI score and total GHQ-28 score (r 2 ¼ 0:6; P , 0:0001; at both time points).

Table 3 Areas of pain and associated symptoms reported by the three whiplash groups at baseline (based on the NDI at 6 months post-injury) Recovered Mild pain Moderate/severe N ¼ 29 (%) and disability pain and disability N ¼ 30 (%) N ¼ 17 (%) Neck pain 100 Headache 40 Shoulder pain 14 Arm pain 7 Thoracic pain 41 Lumbar pain 24 Paraesthesia/anaesthesia 17 Dizziness/unsteadiness 7

100 60 37 23 57 37 13 7

100 88 53 53 94 59 71 42

M. Sterling et al. / Pain 106 (2003) 481–489

485

Table 4 The numbers and types of treatment and medication received by the three whiplash groups Group

Recovered ðn ¼ 29Þ Mild symptoms ðn ¼ 30Þ Mod/severe symptoms ðn ¼ 17Þ

N (%) who received treatment

No. of treatments (average/study period)

Treatment type N (%)

N (%) on medication

PT

CH

AC

14 (48.3) 19 (63) 9 (52.9)

10.6 14.4 18.4

29 (100) 14 (46.7) 8 (47)

0 4 (13.3) 1 (5.8)

0 1 (3) 0

7 (24) 13 (43.3) 12 (70.5)

Medication type SA

NS

Cod

AD

St

Op

3 2 2

4 10 7

1 2 2

0 1 2

1 0 0

0 1 1

Treatment: PT, physiotherapy; CH, chiropractic; AC, acupuncture. Medication: SA, simple analgesics; NS, non-steroidal anti-inflammatory; Cod, codeine; AD, anti-depressants; St, steroids; Op, opioids.

3.3. TSK The marginal means (^ SEM) of the three groups TSK scores are presented in Fig. 3. There was a significant effect for Group ðP ¼ 0:004Þ for TSK scores and an interaction between Group and Time ðP ¼ 0:01Þ: At entry into the study, TSK scores of the moderate/severe and mild groups were 40.05 ^ 2.49 and 38.1 ^ 2.3 (estimated mean ^ SEM) which were significantly greater than that of the recovered group (31.94 ^ 1.9) recovered. TSK scores of the mild group significantly improved ðP ¼ 0:01Þ and by 2 months were no longer different from those of the recovered group. TSK scores of the moderate/severe group remained unchanged until 6 months post-injury when they significantly decreased ðP ¼ 0:01Þ and at this time point were no longer different

Table 5 Mean (SD) scores of each group over time for the four sub-components of the GHQ-28 Recovered

Mild pain and disability

Moderate/severe pain and disability

Somatic symptoms ,1 month 6.9 (0.77) 2 months 4.7 (0.78) 3 months 4.1 (0.83) 6 months 3.5 (0.77)

9.8 (0.74) 9.2 (0.77) 5.6 (0.77) 6.7 (0.73)

12.3 (1.0) 11.7 (1.1) 10.8 (1.0) 9.9 (0.9)

Anxiety/insomnia ,1 month 4.2 (0.8) 2 months 2.9 (0.9) 3 months 2.5 (0.9) 6 months 1.8 (0.8)

8.5 (0.8) 7.1 (0.8) 5.7 (0.8) 5.3 (0.8)

12.5 (1.1) 10.7 (1.2) 10.0 (1.1) 10.3 (1.1)

Social function ,1 month 2 months 3 months 6 months

11.3 (0.6) 9.7 (0.6) 8.4 (0.6) 7.5 (0.6)

12.7 (0.8) 12.1 (0.9) 12.2 (0.8) 9.3 (0.8)

2.5 (0.7) 1.8 (0.7) 1.1 (0.7) 1.6 (0.7)

4.9 (0.9) 3.6 (0.9) 3.4 (0.9) 4.3 (0.9)

7.6 (0.6) 6.8 (0.6) 6.1 (0.7) 6.2 (0.6)

Severe depression ,1 month 0.9 (0.7) 2 months 0.6 (0.5) 3 months 0.6 (0.5) 6 months 0.5 (0.3)

from the other two groups ðP . 0:14Þ: There was no effect of age or gender on TSK scores ðP . 0:09Þ: There was no significant correlation between NDI score and TSK at either entry into or exit from the study (r 2 ¼ 0:2; P ¼ 0:14; r 2 ¼ 0:1; P ¼ 0:6; respectively). 3.4. IES The marginal means (^ SEM) of the three groups for intrusion, avoidance and total scores of the IES are presented in Fig. 4. There was a significant effect for Group ðP , 0:01Þ and an interaction between Group and Time ðP , 0:01Þ for the intrusion and avoidance subscales as well for the total score of the IES. At entry into the study (, 1 month), the group with moderate/severe symptoms at 6 months had an IES total score of 29.12 ^ 3.1 which was significantly greater than both the recovered group (9.46 ^ 2.3) and the group reporting mild symptoms (13.39 ^ 2.2; P , 0:01Þ: The total score of the moderate/severe group was above the score of 26, which is indicative of a moderate post-traumatic stress reaction (Horowitz et al., 1979). Scores of both the recovered and mild groups significantly decreased by the 2-month assessment point ðP , 0:01Þ: Scores of the moderate/severe group remained unchanged until the 6-month time point when they significantly decreased ðP , 0:01Þ and fell to 23 ^ 13.

Fig. 2. Mean (SEM) total scores of GHQ-28 in each group (recovered, mild pain and disability, moderate/severe pain and disability) at each assessment point.

486

M. Sterling et al. / Pain 106 (2003) 481–489

Fig. 3. Mean (SEM) Tampa scale of kinesiphobia (TSK) scores of each group (recovered, mild pain and disability, moderate/severe pain and disability) at each assessment point.

As can be seen from Fig. 4, at entry into the study (, 1 month), the moderate/severe group showed increased scores on both the intrusion and avoidance subscales when compared to the other two groups ðP , 0:01Þ: Intrusion scores of all three groups decreased by the 2-month mark ðP , 0:01Þ with the moderate/severe group showing further significant improvement by 3 months ðP ¼ 0:01Þ but no change after this point ðP ¼ 0:77Þ: Avoidance scores of both the recovered and mild groups also improved by the 2-month point ðP , 0:01Þ but remained unchanged throughout the study period in the moderate/severe group ðP . 0:06Þ: There was no effect of age or gender on the total IES score or its two components ðP . 0:51Þ: 3.5. SF-36 Results for the SF-36 for the three whiplash groups at each time point and Australian normative data (adjusted for

age and gender) (Australian Bureau of Statistics, 1995) are shown in Fig. 5. There was a significant effect for Group and interactions between Group and Time for all components of the SF-36 ðP , 0:001Þ: At entry into the study, the group with moderate/severe symptoms showed lower scores than the other two groups on all components of the SF-36 ðP , 0:01Þ: The group with mild symptoms demonstrated lower scores than the recovered group on all components ðP , 0:01Þ except general health ðP . 0:05Þ: The group that had recovered by the study completion showed lower scores than the Australian norms on the role physical, bodily pain, vitality, social function and role emotional components. Scores of all three whiplash groups improved over the study period. By 2 months post-injury, the recovered group were no longer different from Australian normative data (Fig. 5) on any component. The group with persistent mild symptoms also improved over time in all components of the test, but scores remained lower than Australian norms at 6 months on the role physical and bodily pain components. The group with moderate/severe symptoms showed improvement in the physical function, bodily pain, vitality, social function and mental health components by 2 months post-injury ðP , 0:01Þ but plateaued after this time point with no further change over the study period ðP . 0:18Þ: Scores of this group for the role physical, general health and role emotional components showed no change over time ðP . 0:08Þ: Scores of the moderate/ severe group remained lower than Australian norms at the 6-month time frame. There was no effect of age or gender on any components of the SF-36 ðP . 0:1Þ; except physical functioning where there was a significant age effect ðP ¼ 0:001Þ:

Fig. 4. Mean (SEM) scores of IES for each group (recovered, mild pain and disability, moderate/severe pain and disability) at each assessment point.

M. Sterling et al. / Pain 106 (2003) 481–489

487

Fig. 5. Radar plot scores of the eight components of the SF-36 for each whiplash group (recovered, mild pain and disability, moderate/severe pain and disability) compared to Australian population norms at each time point (,1, 2, 3 and 6 months post-injury).

4. Discussion This study investigated psychological changes from soon after whiplash injury to 6 months post-injury in both recovered and non-recovered participants. Sixty-one percent of our cohort of 76 volunteers reported ongoing pain and disability of varying degrees at 6 months post-injury, a figure similar to data of previous longitudinal studies (Gargan et al., 1997; Radanov et al., 1995) with 22% comprising the group with persistent moderate/severe symptoms. The results demonstrated that whiplash injury results in initial psychological distress to some extent irrespective of the outcome at 6 months. Elevated levels of psychological distress were present in those who eventually recovered and those with mild symptoms as evidenced by lower scores on mental health components of the SF-36 when compared to Australian population norms. Furthermore, GHQ-28 scores were above the threshold of 23/24 in those with persistent mild symptoms and approached threshold in the recovered group. A closer inspection of data of the recovered group revealed that 11 of the 29 (37%) subjects in this group also showed GHQ-28 scores above threshold. The moderate/severe group showed greater psychological distress on both the GHQ-28 and the SF-36 than the other two groups. These results appear to contrast those of Gargan et al. (1997) who showed that GHQ-28 scores were normal within a week of injury but increased in non-recovered

participants by 3 months. It should be noted that Gargan et al. (1997) recruited subjects who had experienced a rear end collision regardless of symptoms, whereas all our subjects reported neck pain. This tends to suggest that the presence of neck pain may be the precursor for elevated psychological distress seen in our cohort. Psychological distress decreased in all whiplash groups over the duration of the study. In recovered participants and those with mild symptoms at 6 months, this occurred earlier (2 –3 months post-injury) and distress levels returned to population norms. In contrast, whilst those with moderate/severe symptoms also showed an overall decrease in their distress levels, their scores on the GHQ-28 remained above threshold and SF-36 scores below population norms at 6 months post-injury. These decreases in psychological distress scores parallel the decrease in self-reported pain and disability also seen in these two groups (Figs. 1, 2, and 5). However, a surprisingly similar pattern emerged for the group with persistent moderate/severe symptoms. Whilst scores of this group remained elevated at the final 6-month assessment point, they did significantly decrease parallelling changes in NDI score over the study period. These findings support a relationship between reported pain and disability and psychological distress post-motor vehicle crash in both recovered and non-recovered subjects. Fear-avoidance beliefs have been put forward as one important psychosocial factor in predicting disability in low

488

M. Sterling et al. / Pain 106 (2003) 481–489

back pain (Klenerman et al., 1995) but is yet to be investigated in WAD. Despite lack of data, it has been proposed that fear-avoidance beliefs play an important role in the pain and disability reported by patients with whiplash (Nederhand et al., 2002). Both our groups that reported persistent mild or moderate/severe symptoms showed elevated TSK scores at entry into the study (, 1 month post-injury) that were similar to scores reported for chronic low back pain (Crombez et al., 1999). Fear of movement may be justified in the acute stage of injury as a protective mechanism against further injury and to allow healing to occur (Vlaeyen et al., 1995). The results of our study would support this view, where TSK scores of the group with mild symptoms decreased as their pain and disability decreased and dropped to levels similar to the recovered subjects by 2 months. Interestingly, TSK scores of the moderate/severe group remained unchanged until between 3 and 6 months where scores also decreased and were no longer different from those of the other groups at this time point. Furthermore the TSK score of this group at 6 months was 34.5 ^ 2.5, below that reported for chronic low back pain subjects (Crombez et al., 1999). This finding is difficult to interpret, because although the NDI scores did decrease over time, this group continued to report moderate/severe pain and disability at 6 months. Perhaps whiplash patients overcome their fear of movement/re-injury over time. The results of our study also showed no correlation between self-reported pain and disability (NDI) and TSK scores. Preliminary evidence suggests that there are differences in the relationships among fear-avoidance beliefs and pain and disability between cervical spine pain and low back pain (George et al., 2001). The findings of our study may reflect this. There were psychological factors that were unique to the group with persistent moderate/severe symptoms. Only this group demonstrated elevated scores on the IES questionnaire at any point throughout the study. At the initial assessment point (, 1 month post-injury), the total IES score of this group was above 26 indicating a moderate post-traumatic stress reaction (Horowitz et al., 1979). This stress reaction seemed to abate during the study period, remaining in the moderate range until 6 months post-injury where IES total scores of the moderate/severe group decreased to 23.13 ^ 1.5 which has been suggested as being a mild post-traumatic stress reaction. These findings are similar to those of Drottning et al. (1995) who showed elevated IES scores in acutely injured whiplash subjects with higher reported pain levels. However, these authors followed the whiplash subjects to only 4 weeks post-injury, still in the acute stage of injury. Our study demonstrates that the stress reaction following the accident persists into the chronic stage of the injury but does decrease. It is interesting to note that whilst intrusion subscale scores decreased reflecting the decrease in total scores of the moderate/severe group, scores of the avoidance component remained unchanged throughout the study period. This finding may be important with respect to the type of psychological intervention required by

these patients and would tend to suggest that some psychological support will be necessary in order to overcome feelings of avoidance in this group. Further investigation of post-traumatic stress reaction in whiplash injured persons is recommended. In summary, the results of this study demonstrate elevated levels of psychological distress in all those experiencing whiplash injury irrespective of symptom levels. Distress decreases in those who recover and those with lesser symptoms parallelling improvements in pain and disability. Those with persistent moderate/severe symptoms continue to be psychologically distressed and demonstrate an acute post-traumatic stress reaction. These findings together with previous reports of early motor and sensory disturbances occurring in those with persistent moderate/severe symptoms (Sterling et al., 2003a,b) suggest that multidisciplinary intervention provided soon after injury may be the most optimal management approach. Acknowledgements Supported by Suncorp Metway Insurance, Queensland and Centre of National Research on Disability and Rehabilitation Medicine (CONROD).

Appendix A Quebec Task Force Classification of WAD (Spitzer et al., 1995). QTF classification grade

Clinical presentation

0

No complaint about neck pain No physical signs

I

Neck complaint of pain, stiffness or tenderness only No physical signs

II

Neck complaint Musculoskeletal signs including: † Decreased range of movement † Point tenderness

III

Neck complaint Neurological signs including: † Decreased or absent deep tendon reflexes † Muscle weakness † Sensory deficits

IV

Neck complaint and fracture or dislocation

M. Sterling et al. / Pain 106 (2003) 481–489

References Australian Bureau of Statistics, National Health Survey. SF-36 population norms, Canberra 1995;1–37. Borchgrevink G, Stiles T, Borchgrevink P, Lereim I. Personality profile among symptomatic and recovered patients with neck sprain injury, measured by mcmvi acutely and 6 months after car accidents. J Psychosom Res 1997;42:357 –67. Crombez G, Vlaeyen J, Heuts P, Lysens R. Pain-related fear is more disabling than pain itself: evidence on the role of pain-related fear in chronic back pain disability. Pain 1999;80:329 –39. Curatolo M, Petersen-Felix S, Arendt-Nielsen L, Giani C, Zbinden A, Radanov B. Central hypersensitivity in chronic pain after whiplash injury. Clin J Pain 2001;17:306–15. Drottning M, Staff P, Levin L, Malt U. Acute emotional response to common whiplash predicts subsequent pain complaints: a prospective study of 107 subjects sustaining whiplash injury. Nord J Psychiatry 1995;49:293 –9. Gargan M, Bannister G, Main C, Hollis S. The behavioural response to whiplash injury. J Bone Joint Surg 1997;79-B:523–6. George S, Fritz J, Erhard R. A comparison of fear-avoidance beliefs in patients with lumbar spine pain and cervical spine pain. Spine 2001;26: 2139–45. Goldberg D. Manual of the General Health Questionnaire. Windsor: NFERNelson; 1978. Horowitz M, Wilner N, Alvarez W. Impact of Event Scale: a measure of subjective stress. Psychosom Med 1979;41:209– 18. Karlehagen S, Malt U, Hoff H, Tibell E, Herrstromer U, Hildingson K. The effect of major railway accidents on the psychological health of train drivers. J Psychosom Res 1993;37:807 –17. Klenerman L, Slade P, Stanley M, Pennie B, Reilly J, Atchison L, Troup J, Rose M. The prediction of chronicity in patients with an acute attack of low back pain in a general practice setting. Spine 1995;20: 478–84. Kori S, Miller R, Todd D. Kinesphobia: a new view of chronic pain behaviour. Pain Manage 1990;Jan/Feb:35–43. Linton S. A review of psychological risk factors in back and neck pain. Spine 2000;25:1148 –56.

489

Moog M, Quintner J, Hall T, Zusman M. The late whiplash syndrome: a psychophysical study. Eur J Pain 2002;6:283–94. Nederhand M, Hermens H, Ijzerman M, Turk D, Zilvold G. Cervical muscle dysfunction in chronic whiplash associated disorder grade 2. The relevance of trauma. Spine 2002;27:1056–61. Pietrobon R, Coevtaux R, Carey T, Richardson W, De Vellis R. Standard scales for measurement of functional outcome for cervical pain or dysfunction: a systematic review. Spine 2002;27:515 –22. Radanov B, Sturzenegger M, Di Stefano G. Long-term outcome after whiplash injury. A 2-year follow-up considering features of injury mechanism and somatic, radiologic, and psychological findings. Medicine 1995;74:281 –97. Spitzer W, Skovron M, Salmi L, Cassidy J, Duranceau J, Suissa S, Zeiss EL. Scientific monograph of Quebec Task Force on whiplash associated disorders: redefining ‘whiplash’ and its management. Spine 1995;20: 1–73. Sterling M, Treleaven J, Edwards S, Jull G. Pressure pain thresholds in chronic whiplash associated disorder: further evidence of altered central pain processing. J Musculoskelet Pain 2002;10:69–81. Sterling M, Jull G, Vicenzino B, Kenardy J. Sensory hypersensitivity occurs soon after whiplash injury and is associated with poor recovery. Pain 2003a; in press. Sterling M, Jull G, Vizenzino B, Kenardy J, Darnell R. Development of motor system dysfunction following whiplash injury. Pain 2003b;103: 65– 73. Vernon H. The neck disability index: patient assessment and outcome monitoring in whiplash. J Musculoskelet Pain 1996;4:95–104. Vernon H, Mior S. The neck disability index: a study or reliability and validity. J Manipulative Physiol Ther 1991;14:409– 15. Vlaeyen J, Linton S. Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art. Pain 2000;85:317–32. Vlaeyen J, Kole-Snijders A, Boeren R. Fear of movement/reinjury in chronic low back pain patients and its relation to behavioural performance. Pain 1995;363– 72. Ware J, Snow K, Kosinski M, Gandek B. SF-36 health survey: manual and interpretation guide. Boston, MA: The Health Institute; 1993. Wenzel H, Haug T, Mykletun A, Dahl A. A population study of anxiety and depression among persons who report whiplash traumas. J Psychosom Res 2002;53:831.