The correlation of the "Walking Estimated-Limitation Calculated by History" (WELCH) questionnaire with treadmill maximal walking time is not impaired by age, in patients with claudication.

Abstract

The "Walking Estimated-Limitation Calculated by History" (WELCH) questionnaire is a short four-item questionnaire that estimates the walking capacity of a patient in comparison with relatives, friends or people the same age. As such, it should be relatively insensitive to age, yet this has never been tested. A prospective study was performed among 525 patients presenting vascular-type claudication. Patients were grouped into quintiles of age-from quintile 1 for the youngest patients to quintile 5 for the oldest ones. Patients completed a self-administered questionnaire and then had their maximal walking time (MWT) measured on a treadmill. We estimated the coefficient of correlation, the slope and the intercept of the relationship between the WELCH score and the MWT, then the accuracy of a WELCH score under 25 to predict the ability to walk for 5 min on a treadmill. The slopes of the relationships and the correlation coefficients were not significantly different in each quintile, but a significant shift in the intercept of regressing lines was found with age. Nevertheless, the accuracy in predicting treadmill results from the WELCH score with a cut-off point of 25 was, respectively, 68.6, 72.4, 80.0, 72.4 and 73.3 % in quintiles 1, 2, 3, 4 and 5 (p = 0.45). The relationship of MWT on a treadmill and the WELCH score is slightly influenced by age, but a score superior to 25 seems to be of equal discriminatory performance in different quintiles of age to predict the ability to walk for 5 min on a treadmill. This makes this cut-off limit of interest for routine use, regardless of age.