Patient-reported anxiety and depression measures for use in Indian head and neck cancer populations: a psychometric evaluation

BACKGROUND: Head and neck cancers (HNC) are one of the most traumatic forms of cancer because they affect essential aspects of life such as speech, swallowing, eating and disfigurement. HNCs are common in India, with over 100,000 cases being registered each year. HNC and treatment are both associated with considerable anxiety and depression. With increasing multinational research, no suitable measures in Indian languages are available to assess anxiety and depression in Indian HNC patients. This study evaluated the psychometric properties of cross-culturally adapted versions of Zung's self-rating Anxiety Scale (SAS) and the Patient health questionnaire - 9 (PHQ-9) in Tamil, Telugu and Hindi speaking Indian HNC populations. METHODS: HNC patients were recruited from three tertiary cancer centres in India. Patients completed the cross-culturally adapted versions of SAS and PHQ-9. We assessed targeting, scaling assumptions, construct validity (exploratory and confirmatory factor analyses), convergent validity, and internal consistency reliability. RESULTS: The study sample included 205 Tamil, 216 Telugu and 200 Hindi speaking HNC patients. Exploratory and confirmatory factor analyses indicated a two-factor solution for PHQ-9 and four-factor solution for SAS in all three languages. Cronbach's alpha coefficients ranged between 0.717 and 0.890 for PHQ-9 and between 0.803 and 0.868 for SAS, indicating good reliability. Correlations between hypothesized scales were as expected providing evidence towards convergent validity. CONCLUSIONS: This first psychometric evaluation of the measurement properties of Tamil, Telugu and Hindi versions of the SAS and PHQ-9 in large, Indian HNC populations supported their use as severity and outcome measures across the disease and treatment continuum.