Background Ireland has the highest rates of hospitalisations for Chronic Obstructive Pulmonary Disease (COPD) of all OECD countries (369/100,000 in 2017, compared with OECD average of 200/100,000). We analysed national hospitalisation data to investigate the characteristics of these hospitalisations and how they have changed over time to assist in programme planning and identify areas for intervention.

Methods Using Hospital In-Patient Enquiry (HIPE), a national discharge database for episodes of admitted care in acute public hospitals, we undertook a longitudinal review of trends in inpatient hospitalisations for COPD between 2009 and 2017. COPD hospitalisations were identifiable by ICD-10-AM codes J40-J44 and J47. We standardised against two populations: 1) sex-specific rates against the OECD pop and 2) age-sex rates to the Irish population for adults aged 15 years and over

Results The prevalence of overnight hospitalisations increased for females from an age-standardised rate of 367.5/100,000 in 2009 to 393.0/100,000 in 2017, and declined for males 391.6/100,000 to 343.5/100,000. Between 2009 and 2017, age-specific rates in males declined across most age categories, with the decline most pronounced in the 80–84 year age group. In contrast, females saw an increase in rates across the majority of age categories.

In 2017, rates were significantly higher amongst women in each 5 - year age category ≤70 years, apart from the 55–59 year category, where there was no difference. Rates were higher amongst men in each of the three age categories ≥75 years. Our analysis indicates that the disparity between hospitalisations for older men and women has narrowed over the period of our study, owing to increased hospitalisations in women and decreased hospitalisation in men.

Conclusion Our analysis of hospitalisation data has seen a convergence in rates between the sexes and a worrying rise in hospitalisations amongst women, particularly among those less than 70 years. This mirrors trends internationally where women have higher rates of COPD than men throughout most of their lifespan, although it appears that they are especially vulnerable before the age of 65. It is known that women are more susceptible than men to lung damage from cigarette smoke and other pollutants, and recent evidence highlights that they have more severe COPD exacerbations than males, resulting in higher hospitalisations. This study confirms these trends and points to the urgent need to raise awareness of this preventable disease, and tackle the high smoking rates that still prevail in Ireland, particularly in socio-economically deprived areas.