Recent analyses suggest that the WPAI:GH/SHP results in inflated responses for the productivity- at- work and activity impairment questions due to other health problems (Q. 4b and 5b) becasue of double-counting, i.e., some respondents include impairment due to the specific health problem when responding to these questions.  (The other questions do not appear to be affected by double-counting.)   For this reason the WPAI:GH/SHP is not recommended.  A revised version of the questionnaire is now in development.
Updated October 2004