Measuring mouth moisture: a case study in instrument development.

This paper describes the process through which an instrument for measuring mouth moisture was developed. The need to create a means of quantifying mouth moisture was realized while planning studies of oral care. Nursing texts assert that one indicator of successful oral care is "moist mucous membranes," and research on oral care typically names mouth moisture as an outcome variable. Yet the measures used in nursing research to assess mouth moisture have been characterized by imprecision, questionable reliability, and disregard for congruence between conceptual and operational definitions. The paper begins by critiquing the instruments commonly used in mouth care research to assess moisture. Next, the methodical process of building ideas to construct a new instrument is described. Finally, the trials that were conducted to arrive at the instrument's final design, estimates of reliability and validity, and a procedure for use that would preserve the integrity of the instrument are discussed.