Construct validity of the concepts of pain, self-care deficit and impaired mobility was examined in a study of 120 medical-surgical patients.

Factors derived from a factor analysis of the empirical signs and symptoms were : pain-factor and self-care deficit/impaired mobility-factor.

The pain-factor clearly showed discriminant validity by differentiating between those with and without Clinical Nurse Specialist (CNS) - identified diagnosis of pain.

An overlap between the defining characteristics of the diagnoses of self-care deficit and impaired mobility has been suggested in the present sample of patients.

Limitations of the study and recommendations for further research are described.