Validity, reliability and cut-offs of the Patient Health Questionnaire-9 as a screening tool for depression among patients living with epilepsy in Rwanda

• Published in: PloS one Vol. 15; no. 6; p. e0234095
• Main Authors: Sebera, Fidèle, Vissoci, Joao Ricardo Nickenig, Umwiringirwa, Josiane, Teuwen, Dirk E, Boon, Paul E, Dedeken, Peter
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 12.06.2020; Public Library of Science (PLoS)
• Subjects: Acquired immune deficiency syndrome; AIDS; Analysis; Biology and Life Sciences; Comorbidity; Complications and side effects; Correlation; Correlation analysis; Demographic aspects; Depression (Mood disorder); Diagnosis; Epilepsy; Evaluation; Factor analysis; Health care policy; Hospitals; Mathematical models; Medical diagnosis; Medicine and Health Sciences; Mental depression; Mental disorders; Mental health; Neurology; Patients; People and Places; Physical Sciences; Primary care; Psychiatry; Psychologists; Quantitative psychology; Questionnaires; Reliability analysis; Reliability aspects; Reliability engineering; Research and Analysis Methods; Risk factors; Social Sciences; Stability analysis; Structural reliability; Translation; Validity; Rwanda; Belgium; United States > US; Africa
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0234095

PHQ-9 was translated to Kinyarwanda using translation-back translation and validated by a discussion group. For validation, PwE of [greater than or equal to]15 years of age were administered the PHQ-9 and Hamilton Depression Rating Scale (HDRS) by trained psychiatry staff at Visit 1. A random sample of 20% repeated PHQ-9 and HDRS after 14 days to assess temporal stability and intra-rater reliability. Internal structure, reliability and external validity were assessed using confirmatory factor analysis, reliability coefficients and HDRS-correlation, respectively. Maximal Youden's index was considered for cut-offs. Four hundred and thirty-four PwE, mean age 30.5 years (SD ±13.3), were included of whom 33.6%, 37.9%, 13.4%, and 15.1% had no, mild, moderate and severe depression, respectively. PHQ-9 performed well on a one-factor model (unidimensional model), with factor loadings of 0.63-0.86. Reliability coefficients above 0.80 indicated strong internal consistency. Good temporal stability was observed (0.79 [95% CI: 0.68-0.87]). A strong correlation (R = 0.66, p = 0.01) between PHQ-9 and HDRS summed scores demonstrated robust external validity. The optimal cut-off for the PHQ-9 was similar ([greater than or equal to]5) for mild and moderate depression and [greater than or equal to]7 for severe depression. PHQ-9 validation in Kinyarwanda creates the capacity to screen PwE in Rwanda at scores of [greater than or equal to]5 for mild or moderate and [greater than or equal to]7 for severe depression. The availability of validated tools for screening and diagnosis for depression is a forward step for holistic care in a resource-limited environment.