Family Practice Advance Access originally published online on May 29, 2008
Family Practice 2008 25(3):197-201; doi:10.1093/fampra/cmn027
Chronic forearm pain presents as a transient and indistinct pain site in a community setting: results from a UK population survey
1 Centre for Health Sciences, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 2 Newark Street, London, UK
2 The Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
Correspondence to Dr Dawn Carnes, Institute of Health Sciences Education, Barts and The London School of Medicine and Dentistry, 2 Newark Street, London E1 2AT, UK; Email: d.carnes{at}qmul.ac.uk
Received 14 November 2007; Revised 25 March 2008; Accepted 27 April 2008.
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Abstract |
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Objectives. To investigate the prevalence of chronic forearm pain in a non-occupational community setting over a 2-year period.
Method. A longitudinal community-based postal questionnaire survey conducted in the south-eastern quadrant of England.
Results. We received 2493/4172 (60%) responses at baseline and we followed up 429 of these 2 years later: 252 responded (59%). Forearm pain prevalence was 4% at baseline and 5% at follow-up. Over 95% of those with forearm pain had pain in other areas [odds ratio 1.5 (95% confidence interval 1.3–1.7)] and it was most commonly associated with elbow and wrist pain. Seventy-six per cent of those with forearm pain at baseline recovered. At follow-up, 78% of those with chronic forearm pain had new-onset forearm pain.
Conclusions. Persistent forearm pain (pain for over 2 years) was rare and the capacity for recovery was good (76%). Isolated forearm pain as a diagnostic category is of little utility. Treating and managing forearm pain in a site-specific manner is unlikely to be successful owing to its strong association with pain in other areas. In the community, forearm pain laterality was not evident; our findings suggest that forearm pain in the workplace is influenced by different factors to those in a community setting.
Keywords. Chronic pain, community survey, forearm pain.
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Introduction |
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Over recent decades there has been an increase in the incidence of chronic forearm pain, this has been attributed to working practices, in several developed countries.1 The apparent epidemic of repetitive strain injury (RSI) in Australia during the 1980s is well documented.2 This epidemic appeared to have little relationship to changed working practices, and many think that there were important psychosocial and societal components to that epidemic.3 There have been few studies of the natural history of chronic forearm pain in community, as opposed to occupational settings.
Chronic forearm pain has variously been ascribed as work-related upper limb disorder, RSI, occupational cervico-brachial disease, regional fibrositis syndrome and work-related carpal tunnel syndrome.3 It is perhaps most commonly known by the, sometimes controversial, diagnostic label of RSI, a diagnosis which implies causation. Chronic forearm pain has been considered by some to be due to physical pathology directly related to occupational injury1 or vascular restriction causing physiological claudication on exercise of the forearm muscles.4 There are some data to suggest that chronic forearm pain commonly coexists with other painful musculoskeletal problems, such as fibromyalgia.5 If chronic forearm pain is caused by specific forearm problems such as repetitive strain or claudication then it should exist as a separate entity, while if the causes of forearm pain have more in common with other causes of non-specific musculoskeletal pain syndromes such as fibromyalgia or back pain then forearm pain should occur as part of these pain syndromes. We report a community study of the prevalence and natural history of chronic forearm pain and its associations with other musculoskeletal pain over a 2-year period.
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Method |
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We have described our survey techniques in detail elsewhere.6 Briefly, we approached, using a postal survey, a random sample of 4172 adults from 16 general practices predominantly across central and south-eastern quadrant of England that were nationally representative in terms of social class and rural/urban split.6 These practices were part of the Medical Research Council's General Practice Research Framework (GPRF) (http://www.gprf.mrc.ac.uk/).
For both the baseline and follow-up survey, GPs screened the names of those sampled to exclude those whom it would have been inappropriate to approach, e.g. those with malignancy or serious psychiatric/psychological disorders. Appropriate participants were sent, by post, a questionnaire about chronic pain and a reminder 2 weeks later if they had not yet completed and returned the questionnaire.
As part of the baseline survey, we asked respondents if they would be willing to participate in further research, and those who were willing to continue with the research were included in the follow-up survey approximately 2 years later.
Of the original 16 general practices, seven agreed to participate in a follow-up study, two were based in Essex, two in London and one in Berkshire, Kent and Hertfordshire. The reasons for practices not participating were that the original staff involved in the survey had left the practice, they had left the GPRF, they had no resources available or that they were too busy.
The baseline and follow-up survey questionnaires measured the prevalence, patterns, health impact and consulting behaviour for chronic musculoskeletal pain in the community. The questionnaire survey contained a pain drawing (Fig. 1) which provided data about the distribution of pain.
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The questionnaire
In both the baseline and follow-up questionnaire, subjects were asked to shade a pain drawing indicating where they had experienced pain for more than half the days in the last year. The pain drawing illustrated the presence or absence of chronic pain; it was a non-directive method of identifying pain location and the responders were not led, or misled, by common labels or anatomical terminology. Using a bespoke software programme, we were able to record the presence or absence of pain in 15 upper body regions representing the major anatomical regions (Fig. 2). In a related study, we established that when participants shaded an area on the pain drawing, it was indicated as at least ‘moderately troublesome pain’.7
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Definitions of pain distributions
We defined chronic forearm pain as any pain in the area between the elbow and wrist that has been present for at least half the days in the last year. This definition of duration is consistent with that used in other studies of chronic pain8 and the pain distribution is consistent with that used in the previous community study of forearm pain.3 To avoid the risk that diagnostic labelling implies either causality or a pathological cause for a painful symptom, for this study, we to refer to the problem as forearm pain.
Ethical review
The London Multi-centre Ethics Committee provided ethical review.
Analysis
We calculated the prevalence of upper body, forearm and isolated forearm pain. The standardization rate for chronic pain was calculated using data from the 2001 British census. To assess the relationship between painful body areas, the phi correlation coefficient was used. Each location was correlated with every other location for the presence or absence of pain.9
To assess the course of forearm pain over the follow-up period, we used paired data from those who responded to both surveys. A diagram was constructed using baseline and follow-up data to identify forearms that had recovered, remained persistent or developed new forearm pain.
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Results |
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Sixty per cent (2493/4172) responded to the baseline survey. The mean age of responders was 52 years (range 18–102). Of our sample, 44% (1097) were male. Forty-four per cent (1086) of the sample had chronic pain (pain for more than half the days in the last year). Of these, 43% (465) were male. Non-responders in both the baseline and follow-up surveys were more likely to be males, younger and working.
Seven of the original 16 participating baseline practices were able to participate in the follow-up survey, giving a baseline total of 978 respondents. Fifty-five per cent of the participating practices baseline respondents were willing to take part in the follow-up (540); of these, 111 (21%) were excluded by their GPs due to death, terminal illness, psychologically inappropriate or that they had left the practice. Four hundred and twenty-nine people were sent a follow-up questionnaire, 252 returned the questionnaires (this equates to 10% of baseline responders, 26% of the potential 978 and 59% of those who were sent a second follow-up questionnaire, 252/429).
Table 1 shows the characteristics of the responders at baseline and follow-up. At baseline, crude chronic pain prevalence was 44%, this increased with age and peaked at 54–59 years and was more prevalent in females (57%). The corrected prevalence after standardizing for age and sex was 18.6%. At follow-up, 57% of the sample had chronic pain. Those who responded to the follow-up survey were more likely to have pain than those responding to the baseline survey.
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Prevalence of upper body pain
Ninety-four respondents reported forearm pain in their left, right or both arms at baseline (4% of the baseline sample), and 32% (30) were male. At follow-up, there were 13 respondents (5% of the total follow-up sample of 252) having left, right or bilateral forearm pain, and 62% (8) were male. Of those with forearm pain at baseline, 36% (34/94) had left-sided pain, 40% right (38/94) and 23% (22/94) had bilateral pain. At follow-up, 8% (1/13) had left forearm pain and 44% (7/13) right and 38% (5/13) had bilateral pain.
Figure 1 shows the distribution of pain in each upper body area and it illustrates very little laterality in pain. Regardless of gender, upper body pain was almost equal left and right at baseline.
Forearm pain rarely occurred in isolation and over 95% of those with forearm pain had pain in other areas [odds ratio 1.5 (95% confidence interval, 1.3–1.7)] and it was most commonly associated with elbow and wrist pain on the same side and forearm pain on the opposite side (r = 0.3–0.5, P < 0.01). There were four cases of single-site right forearm pain, prevalence 0.16% and no recorded incidences of single-site left forearm pain.
Forearm pain over 2 years
Figure 2 shows the progress of pain over a 2-year period. We used paired data from those responding to both the baseline and follow-up surveys. One unique identifying number code was spoiled so we could not match questionnaires; this resulted in using 251 pairs of data giving a total of 502 forearms to analyse. Figure 3 shows the amount of change in forearm pain over the 2 years. In this sample, 17 respondents had forearm pain at baseline, 76% (13) of these recovered and 24% (4) continued to have forearm pain. Fourteen of the 18 (78%) with forearm pain at follow-up had developed new forearm pain after the baseline survey, showing change over time.
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Discussion |
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Our aim was to explore the prevalence, pattern of forearm pain and its progress over a 2-year period, in a community sample. The results showed that forearm pain prevalence was low, 4% at baseline with an almost equal prevalence in the left and right forearms. Few respondents had forearm pain in isolation and nearly all had pain elsewhere. Further investigation revealed that adjacent areas were most commonly associated with forearm pain. The change in pain between surveys was more than we expected from a population with reported chronic pain from the previous year (Fig. 3).
Forearm pain prevalence and laterality
We found the prevalence of chronic of forearm pain (between the wrist and the elbow) to be 4%. Previous studies report a 7-day prevalence of 4.3% and a 1-year incidence of 1.3% in a cohort of computer workers10 and a 1-month prevalence of combined wrist and forearm pain of 9% in a cohort of 12 types of occupational groups.11 Another reported a 1-month prevalence of forearm pain (between the wrist and the elbow) to be 8% in a community survey at follow-up.3 Several studies observed as we did that forearm pain rarely occurred in isolation.3,10,11 We postulate that this lessens its meaningfulness as a diagnostic category. Forearm pain laterality was not evident in our community sample, suggesting that occupational factors may not have a major role in the causation of forearm pain generally. Although we did not ask about dominance, it is estimated that 90% of the UK population are right handed.12 If forearm pain was occupational in origin, we would expect a higher prevalence in the dominant hand.
Chronic forearm pain rarely exists in isolation
Forearm pain was part of a pain complex; it was significantly associated with the wrist and elbow pain on the same side and forearm pain on the opposite side. Predictors of forearm pain include repetitive movement of the arm or wrist,3,11 mouse use of more than 30 hours and keyboard use of more than 15 hours.10 Other associated risk factors include high job demands,10 psychological distress13 and pain in at least two other areas.3 We also found that forearm pain rarely existed in isolation.
Forearm pain was not as persistent as we thought
Our data showed that there was reasonable change in pain state over 2 years in those with baseline forearm pain. More responders improved and recovered (76%) than those remaining the same or worsening (24%), thus indicating that forearm pain may be less static and chronic than originally thought. Epidemiological reports normally present overall prevalence data which does not distinguish between those who recover and move out of the prevalence data and those who have new onset of pain.
Issues with this research and other studies in this field
The definition of forearm pain was not consistent between the studies reviewed for this paper. We sourced several definitions of forearm pain, prevalence and chronicity. The main problem with researching isolated forearm pain in the general population is that the prevalence is low. The average prevalence of forearm pain generally appears to be approximately 4%; such low figures affect the power of the data used for statistical analyses. The problem is exacerbated by loss at follow-up, as seen in this study. The power of the data presented in this study is limited but the pain patterns, distributions and changes over time indicate that further research is needed to fully appreciate the natural history and course of forearm pain in non-occupational settings.
A further issue is responder bias; our data does show that those with chronic pain were more likely to respond to the survey. However, as we were interested in those with pain and the patterns and change of pain over time, this will have had relatively little impact on our findings.
This study used a pain drawing to identify locations of pain; this meant that site of pain could be determined post hoc. Respondents were not led by diagnostic labelling and poorly understood anatomical terminology. We also know from other research that pain drawings represent both, location of pain and pain that is significant to the individual completing the pain drawing.7 We could not determine aetiology of pain in this study but we could investigate chronicity. The pain drawing also enabled us to investigate chronic pain elsewhere and explore pain commonly associated with forearm pain.
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Conclusions |
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Our study indicated that, in the community, chronic forearm pain prevalence was low, meaning isolated forearm pain is an unlikely diagnostic category in epidemiological terms. As forearm pain rarely existed in isolation, measuring, researching, managing and treating forearm pain on its own is unlikely to be satisfactory for the patient, clinician or the researcher.
Persistent forearm pain coexisted with pain in other areas but overall the prognosis of chronic forearm pain in the community was good. Predictors of new-onset forearm pain are unlikely to be simple and further exploration of this area may suit qualitative rather than quantitative research methods. The attention to forearm pain in the workplace is disproportionate to its overall impact in the community, where it appears less of an issue.
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Declaration |
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Funding: Arthritis Research Care; the Assurance Medical Society; Barts and The London Joint Research Board.
Ethical approval: The study was approved by the London Multi-Centre Research Ethics Committee.
Conflicts of interest: None.
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Acknowledgments |
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We thank the Musculoskeletal Process of Care and Collaboration, A. Breen, N. Foster, T. Pincus, MU and S. Vogel for advice.
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Notes |
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Carnes D, Ashby D, Parsons S and Underwood M. Chronic forearm pain presents as a transient and indistinct pain site in a community setting: results from a UK population survey. Family Practice 2008; 25: 197–201.
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References |
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