Quality appraisal of generic self-reported instruments measuring health-related productivity changes: a systematic review

Table 4 Level of evidence per measurement property per instrument

Instrument and paper	Internal consistency	Reliability	Measurement error	Content validity	Structural validity	Hypotheses testing	Cross-cultural validity	Criterion validity	Responsiveness
WLQ[19, 21, 26–28, 36, 37, 42]	+/-	-	N.A.	++	+++	--	N.A.	+/-	--
EWPS[19, 29]	?	?	N.A.	N.A.	N.A.	+/-	N.A.	?	?
WPAI[19, 22, 39]	?	?	?	N.A.	N.A.	--	N.A.	--	?
WPSI[19, 21, 31]	?	?	N.A.	?	N.A.	?	N.A.	+/-	?
AMA-guides[30]	N.A.	?	N.A.	N.A.	N.A.	?	N.A.	?	N.A.
WHO-HPQ[32, 33]	N.A.	-	N.A.	+++	+	+/-	N.A.	+/-	?
SPS[34, 41]	+++	-	N.A.	-	+++	++	N.A.	++	N.A.
PRODISQ[24]	N.A.	N.A.	N.A.	+++	N.A.	N.A.	N.A.	N.A.	N.A.
HRPQ-D[35]	N.A.	-	N.A.	?	N.A.	?	N.A.	-	-
HLQ[20, 25]	N.A.	-	N.A.	N.A.	N.A.	N.A.	N.A.	--	N.A.
Q&Q[20]	N.A.	-	N.A.	N.A.	N.A.	N.A.	N.A.	-	N.A.
WBA-P[38]	N.A.	N.A.	N.A.	N.A.	+	N.A.	N.A.	+	N.A.
HWQ[40]	+	N.A.	N.A.	N.A.	-	N.A.	N.A.	-	?
WHI[43]	N.A.	-	N.A.	N.A.	N.A.	N.A.	N.A.	-	-
VOLP[23]	N.A.	+	N.A.	N.A.	N.A.	N.A.	N.A.	-	N.A.

WLQ = Work Limitations Questionnaire; EWPS = Endicott Work Productivity Scale; WPSI = Work Productivity Short Inventory; WPAI = Work Productivity and Activity Impairment Instrument; AMA-guide = American Medical Association-Guides; WHO HPQ = World Health Organization Health and work Performance Questionnaire; SPS = Stanford Presenteeism Scale; PRODISQ = PROductivity and Disease Questionnaire; HRPQ-D = Health-Related Productivity Questionnaire Diary; HLQ = Health and Labor Questionnaire; Q&Q = Quality and Quantity questionnaire; WBA-P = Well-Being Assessment for Productivity; HWQ = Health and Work Questionnaire; WHI = Work and Health Interview; VOLP = Valuation of Lost Productivity questionnaire N.A. = Not Available; +++ = Strong positive level of evidence; ++ = Moderate positive level of evidence; + = Limited positive level of evidence; - = Limited negative level of evidence; -- = Moderate negative level of evidence; +/- = Conflicting level of evidence; ? = Unknown level of evidence due to poor methodological quality.

ISSN: 1471-2458