In 2005 Professor Chris Salisbury and colleagues developed a short questionnaire to assess patients' satisfaction with out of hours services in primary care and validated it in comparison to a longer validated questionnaire.
It can be used free of charge as long as the publication below is referenced in any report based on use of the questionnaire.
Salisbury C, Burgess A, Lattimer V, Heaney D, Walker J, Turnbull J et al. Developing a standard short questionnaire for the assessment of patient satisfaction with out-of-hours primary care. Family Practice 2005; 22(5):560-569. http://dx.doi.org/10.1093/fampra/cmi050