Recurrence of low back pain: definition-sensitivity analysis using administrative data.

Area of Science:

• Occupational health
• Epidemiology
• Health services research

Background:

• Previous studies on low back pain recurrence report rates from 14% to 45%.
• Inconsistent definitions of recurrence and follow-up periods limit the comparability of existing research.
• Understanding recurrence is vital for effective workers' compensation management.

Purpose of the Study:

• To evaluate how different definitions and follow-up parameters affect low back pain recurrence rates.
• To analyze recurrence using administrative claims data from a workers' compensation system.
• To provide a basis for standardized reporting of low back pain recurrence.

Main Methods:

• Retrospective analysis of 2944 new low back pain workers' compensation claims from 1996-1997.
• Defined recurrence by new claims, new episodes of care, or new lost work time (work disability).
• Examined various minimum between-episode gaps and two follow-up structures up to 3 years.

Main Results:

• Claims-based recurrence rates were 7.9% (entire cohort) and 7.1% (work disability subset) over 3 years.
• Care-based recurrence rates varied widely (12%-49%), while disability-based rates ranged from 6%-17%.
• Recurrence rates were inversely related to the length of the minimum between-episode gap (R = -0.86, P < 0.001); 2-year follow-up captured 85%-100% of recurrences.

Conclusions:

• Low back pain recurrence rates are highly sensitive to definition variations.
• Standardized definitions and consistent application are necessary for valid cross-study comparisons.
• This study highlights the impact of methodological choices on observed recurrence rates.