The Prevalance of Depression amongst People with Chronic Obstructive Pulmonary Disease on Long Term Oxygen Therapy

Aim: To determine the prevalence of depression amongst people with chronic obstructive pulmonary disease (COPD) on long term oxygen therapy (LTOT) and examine the differences and relationships between depressed and not depressed patients to inform clinical practice. Methods: In September 2009 a cross-sectional point prevalence study of the total District Health Board (DHB) population of COPD patients on LTOT oxygen in a large urban area in New Zealand (NZ) was conducted. Depression was assessed using the self-completed Patient Health Questionnaire (PHQ-9). Additional clinical and demographic characteristics were obtained from hospital records and a self-completed questionnaire. Results: Sixty three patients (36 females, mean age 72) from the total population of 73 with severe COPD (forced expiratory volume in one second [FEV1] 37% predicted) completed the survey. PHQ-9 results indicate the total prevalence of depression was 54%; 95% CI 41.71-65.87. Twenty five percent of patients had mild depression and 29% had moderate to severe depression. One in six patients of those who screened positively was being treated for depression. No significant correlations or differences were found between the depressions scores and the demographic (age, gender, lives alone) or clinical (portable oxygen, time on oxygen, hospital admissions, pulmonary rehabilitation and FEV1) characteristics. Conclusion: This study provides new evidence regarding the prevalence of depression in NZ COPD LTOT populations. Depression symptoms and depression are highly prevalent in this patient population and there is evidence depression is undertreated. The PHQ-9 is a simple and effective tool community nurses can use for the initial screening of depression, which could improve the recognition and possible uptake of effective interventions to lessen the impact of depression in this population. The PHQ-9 is validated screening tool that should be used in further depression prevalence research with NZ COPD and other long-term condition populations to determine homogeneity across studies