Objective To review studies of anxiety in critically ill patients admitted to an intensive care unit to describe the level of anxiety and synthesize the psychometric properties of the instruments used to measure anxiety.
Methods The CUIDEN, IME, ISOC, CINAHL, MEDLINE, and PSYCINFO databases for 1995 to 2005 were searched. The search focused on 3 concepts: anxiety, intensive care, and mechanical ventilation for the English-language databases and ansiedad, cuidados intensivos, and ventilación mecánica for the Spanish-language databases. Information was extracted from 18 selected articles on the level of anxiety experienced by patients and the psychometric properties of the instruments used to measure anxiety.
Results Moderate levels of anxiety were reported. Levels were higher in women than in men, and higher in patients undergoing positive pressure ventilation regardless of sex. Most multi-item instruments had high coefficients of internal consistency. The reliability of instruments with only a single item was not demonstrated, even though the instruments had moderate-to-high correlations with other measurements.
Conclusion Midlength scales, such the anxiety subscale of the Brief Symptom Inventory or the shortened state version of the State-Trait Anxiety Inventory are best for measuring anxiety in critical care patients.