Determination of sciatica in epidemiologic research.

The international classification of diseases is unsuitable for epidemiologic research on the etiology of degenerative back disease. In cross-sectional studies of occupationally active populations, the occurrence of various symptoms and signs of back disease may be established. However, recommendations as to what data to gather or how to combine it into meaningful entireties are not yet established. To validate reported sciatic pain by clinical findings, 252 reinforcement workers and 231 painters, all men, 20-64 years of age, were examined by nine tests. In the reinforcement workers exposed to heavy occupational loads the reports of sciatica during the previous month were clearly related to several clinical findings. The tests for restriction and pain on bending forward and sideward gave sensitivity values of 0.36-0.61 and specificity values of 0.82-0.87. Combining the results of the separate tests into pairs enhanced the sensitivity to 0.62-0.68, but reduced the specificity to 0.77-0.78. Referring to the current results, recommendations include a structured inquiry into sciatic pain during the previous month, backed up by clinical tests for range of and pain on lumbar movement, when studying the occurrence of back syndromes in physically heavy trades.