Evaluating patient's knowledge of maternal serum screening.

The objective was to describe the development, characteristics, and initial use of an instrument for assessing knowledge about maternal serum screening (MSS). Items for a knowledge scale were selected based on a review of educational materials, the literature, and expert opinion. Items were pre-tested for comprehensibility and ambiguity in a convenience sample. After extensive pre-testing and pilot testing a 14-item scale, the Maternal Serum Screening Knowledge Questionnaire (MSSKQ) was developed. It was administered to 1084 women attending a maternal registration clinic. The overall knowledge score was compared across socio-demographic groups, and by sources of information about MSS. Mean MSSKQ scores increased with age, education, and family income, and among those reporting having an opportunity to discuss MSS and receiving written material. The MSSKQ is a reliable instrument with good content and construct validity. This tool should be valuable in assessing knowledge and level of informed consent in women receiving MSS and in evaluating the implementation of MSS programmes.