Hallifax RJ, et al. - Using large, longstanding hospitalization data sets in England, researchers estimated the incidence of hospital admissions for spontaneous pneumothorax, its recurrence, and its trends over time. Compared with females, the population-based rate per 100,000 population aged ≥ 15 years was higher for males. Findings from this investigation provided contemporary information on trends in hospitalization for spontaneous pneumothorax.

Methods

• Using an English national data set and an English regional data set, researchers conducted a population-based epidemiological study, each spanning 1968-2016, and including 170,929 hospital admission records of patients aged ≥ 15 years.
• December 31, 2016 was the final date of the study period.
• Calendar year (for incidence) and readmission to hospital for spontaneous pneumothorax (for recurrence) were the main exposures analyzed.
• Rates of hospital admissions for spontaneous pneumothorax and recurrence, defined as a subsequent hospital readmission with spontaneous pneumothorax, were the primary outcomes.
• They used record-linkage to identify multiple admissions per person and comorbidity.
• Using cumulative time-to-failure analysis and Cox proportional hazards regression, risk factors for recurrence over 5 years of follow-up were assessed.

Results

• Data indicated that there were 170,929 hospital admissions for spontaneous pneumothorax (median age, 44 years [IQR, 26-88]; 73.0% male) from 1968-2016.
• In 2016, there were 14.1 spontaneous pneumothorax admissions per 100,000 population aged ≥ 15 years (95% CI, 13.7-14.4), a significant increase vs earlier years, up from 9.1 (95% CI, 8.1-10.1) in 1968.
• They observed that the population-based rate per 100,000 population aged ≥ 15 years was higher for males (20.8 [95% CI, 20.2-21.4]) than for females (7.6 [95% CI, 7.2-7.9]).
• They found that, among patients with spontaneous pneumothorax, 60.8% (95% CI, 59.5%-62.0%) had chronic lung disease.
• Record-linkage analysis showed that the overall increase in admissions over time could be due in part to an increase in repeat admissions.
• However, there were also significant increases in the annual rate of first-known spontaneous pneumothorax admissions in some population subgroups, such as that observed in women aged 65 years and older (annual percentage change from 1968-2016, 4.08 [95% CI, 3.33-4.82], P < 0.001).
• Findings revealed that the probability of recurrence within 5 years was similar by sex (25.5% [95% CI, 25.1%-25.9%] for males vs 26.0% [95% CI, 25.3%-26.7%] for females); however, there was variation by age group and presence of chronic lung disease. For example, the probability of readmission within 5 years among males aged 15 to 34 years with chronic lung disease was 39.2% (95% CI, 37.7%-40.7%) vs 19.6% (95% CI, 18.2%-21.1%) in men aged 65 years and older without chronic lung disease.