# Predictive Validity of the Patient Health Questionnaire‐9 for Depression in Poststroke Patients: A Systematic Review and Meta‐Analysis

## TL;DR

This study confirms that the PHQ-9 is a reliable tool for screening depression in stroke patients, but optimal cut-off values need to be determined for better accuracy.

## Contribution

The study provides a meta-analysis of the PHQ-9's diagnostic accuracy for poststroke depression and evaluates the impact of different cut-off values.

## Key findings

- The PHQ-9 showed high pooled sensitivity and specificity for poststroke depression screening.
- Cut-off values significantly affect the test's sensitivity and specificity.
- No publication bias was found in the included studies.

## Abstract

The Patient Health Questionnaire‐9 (PHQ‐9), known for its brevity and ease of use, is employed by researchers and clinical practitioners for poststroke depression (PSD) screening. However, the effectiveness of the PHQ‐9 in PSD screening remains to be further validated.

Electronic searches were conducted in EMBASE, PubMed, Web of Science, CNKI, and Wanfang databases using keywords including stroke, depression, and PHQ‐9. The assessment tool Quality Assessment of Diagnostic Accuracy Studies‐2 was utilized to evaluate the risk of bias in diagnostic studies.

A total of 2049 articles were retrieved, with 9 meeting the inclusion criteria. The PHQ‐9 demonstrated pooled sensitivity and specificity of 0.84 and 0.90, respectively, and a summary receiver operating characteristic (sROC) curve of 0.93. At the 10‐cut‐off value, pooled sensitivity, specificity, and sROC were 0.77, 0.85, and 0.86, respectively. At the 9‐cut‐off value, the sensitivity, specificity, and sROC were 0.87, 0.85, and 0.92, respectively. At the 5‐cut‐off value, sensitivity, specificity, and sROC are 0.90, 0.91, and 0.96, respectively. No publication bias was identified.

The PHQ‐9 is an effective tool for screening poststroke depressive symptoms with significant clinical utility. However, further research is needed to establish optimal diagnostic thresholds.

This meta‐analysis confirms the high accuracy of the Patient Health Questionnaire‐9 (PHQ‐9) in screening poststroke depression. The findings highlight the impact of varying cut‐off values on sensitivity and specificity, emphasizing the need for tailored diagnostic thresholds to enhance clinical applicability across different populations.