Measurement of Irritability in Cancer Patients.

ABSTRACT

BACKGROUND: Irritability is common among people who are physically ill, but a physical underpinning of irritability is not assessed by existing measures. A measure that assesses multidimensionality of irritability can help nurses and clinicians provide better care for people with cancer and, thus, reduce a risk for developing depression during cancer treatment. OBJECTIVES: We pilot tested a new measure, The Irritability Scale-Initial Version (TISi), for assessing irritability of cancer patients on three dimensions physical, affective, and behavioral. METHODS: We conducted thee pilot studies to develop the 35-item TISi on a 5-point Likert scale. TISi was tested in 48 early-stage, nonmetastasized breast cancer patients at baseline (before) and 3 months (during chemotherapy). Of these patients, 62.5% received neoadjuvant and 37.5% received adjuvant chemotherapy, but none received hormonal treatment before or during the study. Measures of other correlates, including depression, anxiety, symptom distress, and social disconnectedness, were also administered, and biomarkers of hsCRP, TNF-α, IL-6, and BDNF were obtained from blood draws at both assessments. RESULTS: TISi has a high internal consistency (Cronbach's α = .97), satisfactory test-retest reliability (retest r = .69, intraclass correlation coefficient = .86), and moderate correlation with other constructs over time (r ≈ .40-.70). Its physical subscale significantly correlated with hsCRP (r = .32, p = .025) at baseline and TNF-α (r = .44, p = .002) at 3 months. A confirmatory factor analysis yields three factor loadings that are in line with conceptualization of the subscales. DISCUSSION: The findings support psychometric properties of TISi and its application for assessing cancer patients' irritability in multiple dimensions. Further investigation using a large study sample is necessary for improving construct and criterion validity and reducing item redundancy. CONCLUSION: TISi can be used to measure the level of irritability in cancer patients.