It is important to validate self-reported musculoskeletal pain used in epidemiological studies for evaluation of pain outcome measures. The main objective of this paper was to assess the association between self-reported neck/shoulder/upper limb pain and clinical signs of disorders in the region, especially by comparing a measure that only used pain intensity with a measure that combined pain intensity and pain duration.
Four hundred and twenty technical school students of both genders were included with a median age of 17 years (16-28). The students stated the pain in four intensity grades and the pain duration in four period lengths within the preceding four weeks period. A pain severity index was calculated by multiplying the pain intensity (0-3) and the duration (1-4). A clinical examination was performed within a week after completing the form. The associations were evaluated by agreement, correlation and symmetric strength of association (contingency).
The study found low correlation and low positive agreement for neck/shoulder and upper limb pain related to clinical signs of disorders in the region. However, the relationship showed high negative agreement and high contingency. The negative agreement increased for the neck/shoulder region with higher cut-off points for dichotomization, but not for the upper limb region. The index combining reports of pain intensity with pain duration, do not improve agreement, correlation or contingency with clinical signs compared to use of pain intensity alone.
This study showed an association between self-reported neck/shoulder/upper limb pain intensity and clinical signs of musculoskeletal disorders of the region. An index combining pain intensity and duration (Pain Severity Index) did not increase this association. From the results we suggest using pain intensity reports alone and if dichotomizing is wanted, choosing a cut-off point at high pain levels, especially for neck and shoulder pain.

BACKGROUND: Musculoskeletal disorders (MSD) caused by occupational-related factors continue to place huge burdens on global workforces. Significant numbers of workers report potential adverse health outcomes related to the condition, such as physical injury, disability, and decline in quality of life. Occupational-related MSD also poses additional burdens to healthcare services and diminishes productivity at work. The condition usually worsens in informal sectors where the work environments are often poorly designed. This paper explored occupational and physical environmental factors that induce work-related neck and/or shoulder pains among self-employed tailors in Gondar city, Northwest Ethiopia.
METHODS: We conducted across-sectional survey from April to May 2019 on 422 tailors selected with systematic random sampling technique. Nordic Musculoskeletal questionnaire was used to measure pains in neck and/or shoulder, and the questionnaire was pretested and administered by interviewers. Work-related factors such as working posture, rest break, training in safety and health, and the availability of adjustable chairs at workplaces were assessed. The significance of associations was set at a < 0.05 p-value and adjusted odds ratios (AOR) with a confidence interval (CI) of 95% were used to determine strength of associations.
RESULTS: A total of 419 tailors participated with a response rate of 99.3%. The mean age and mean years of experience were 29.23 (SD ± 7.03) and 1.48 (SD ± 0.50) years, respectively. The study found that the prevalence of pain in either neck or shoulder or both sites in the last 12 months was 66.6% (N = 279) [95% CI (62.1, 71.1)]. Pains in shoulder and neck were observed in 72.1% (N = 302)[95% CI (67.8, 76.4)] and 68.3% (N = 286) [95% CI (64.0, 72.6)] of the interviewees, respectively. The majority, 78.1% (n = 218) of those with pains indicated they were prevented from doing normal daily activities. Work experience (AOR = 1.81), rest break (AOR = 2.13), awkward working posture (AOR = 2.60), prolonged sitting (AOR = 2.00) and inadequate light (AOR = 5.02) were significantly associated factors of neck and/ or shoulder pains.
CONCLUSIONS: Work-related neck and/or shoulder pain induced by physical factors of the work environment among self-employed tailors is pervasive in Ethiopia. Efforts to curb the condition, therefore, need to impalement diverse approaches addressing the physical environment and occupational factors. We also promote the integration of schemes for the effective use of rest breaks into health and safety programs in the workplace.