A critique of a UK standardized test of finger rewarming after cold provocation in the diagnosis and staging of hand-arm vibration syndrome.
BACKGROUND
Accurate diagnosis and staging of hand-arm vibration syndrome (HAVS) is important in health surveillance of vibration-exposed workers and the substantial number of related medico-legal cases. The measurement of the rewarming rate of fingers after cold provocation to the hands (CPT) has been suggested as a useful test in diagnosing HAVS.


OBJECTIVE
To investigate the diagnostic value of a standardized version of the CPT test using a 15 degrees C cold challenge for 5 min applied in the recent compensation assessment of UK miners.


METHODS
Analysis of a subset of UK miners assessed at our unit, together with data from a small repeatability study of the standardized CPT in normal subjects.


RESULTS
Rewarming time in the CPT was significantly lower in those subjects classified as vascular Stockholm stage 0 compared with Stockholm stages 1-3 combined, but did not discriminate between the stages of abnormality. Using the suggested cut-off in the CPT test, the sensitivity and specificity were calculated as 43 and 78%, respectively. Receiver operator characteristic analysis suggested that the rewarming time of highest accuracy gave a sensitivity of 66% and specificity of 59%. In 10 miners who reported unilateral hand blanching, there was no significant difference in CPT measurements between blanching and non-blanching hands. Repeat CPT measurements in normal subjects suggested mean differences of 52 and 107 s for each hand, and the Bland-Altman coefficient of repeatability was approximately 600 s for all fingers.


CONCLUSIONS
Single application of this standardized CPT test may have limited value in diagnosing the vascular component of HAVS in an individual.
Mason
H J
HJ
Health and Safety Laboratory, Broad Lane, Sheffield S3 7HQ, UK. howard.mason@hsl.gov.uk
Poole
K
K
Saxton
J
J
D000328:Adult; D000368:Aged; D001134:Arm Injuries / Q000150:complications / Q000175:diagnosis*; D003032:Coal Mining; D003080:Cold Temperature; D012090:Cumulative Trauma Disorders / Q000150:complications / Q000175:diagnosis*; D003955:Diagnostic Tests, Routine / Q000379:methods; D005385:Fingers; D006230:Hand Injuries / Q000150:complications / Q000175:diagnosis*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis*; D016491:Peripheral Vascular Diseases / Q000175:diagnosis / Q000209:etiology; D011928:Raynaud Disease / Q000175:diagnosis; D012680:Sensitivity and Specificity; D013577:Syndrome; D006113:United Kingdom; D014732:Vibration / Q000009:adverse effects*