Changes Made

Page 330, ‘Background’ section, column 2, final sentencenow reads:

“Additionally, we provide data supporting the validity of the Work Productivity Questionnaire (WPQ) in this population.”

Page 331, ‘Productivity Instrument’ section, paragraph 2, first sentence now reads:

“The WPQ is an abbreviated version of the Work Limitations Questionnaire (WLQ)®,[25] which captures four domains of work: (i) physical; (ii) time management; (iii) mental; and (iv) output demands.”

Page 331-2, ‘Productivity Instrument’ section, paragraph 3, third sentence and subsequent equation have been removed.

Page 332, column 1, paragraph 2, first sentencenow reads:

“The extent of productivity impairment was estimated by the Work Productivity Loss Score (WPLS), which could range from 0 (best) to 25 (worst) percent and estimates decreases in work output compared with healthy individuals.”

Page 332, column 1, paragraph 2: The following text has been added after the end of the first sentence:

“Further information regarding calculation of the WPLS can be obtained by contacting wlq@tuftsmedicalcenter.org.”

Page 332, figure 1: The figure and legend have been replaced with the following:

Fig. 1
figure 1

Concepts measured in the Work Productivity Questionnaire (WPQ).

Full size image

Note

All online versions of this article have been updated to reflect these changes.