RECURRENCE OF PRIMARY SPONTANEOUS PNEUMOTHORAX

Background - Primary spontaneous pneumothorax (PSP) is a common clinic al problem and its incidence is thought to be increasing. The risk of recurrence is high and various studies quote rates of 20-60%. Factors which may or may not predispose to recurrence have not yet been establ ished. Methods - In a study period of four years 291 cases with a diag nosis of pneumothorax were reviewed; 153 patients with PSP were includ ed in the study. Their risk of recurrence was analysed with particular reference to the following variables: age, sex, height and body mass index (BIMI) of the patient, the initial size of pneumothorax, the smo king status of the patient, and the primary form of treatment employed . Univariate analysis was carried out by chi(2) testing and multivaria te analysis was calculated by a logistic regression model. Results - A retrospective study of 275 episodes of PSP in 153 patients over a fou r year period confirmed a high incidence of recurrence (54.2%). PSP wa s twice as common in men as in women, though women were significantly more likely to develop a recurrence (chi(2)=7.58, df=1, p<0.01). Male height was the second most important factor, and smoking cessation the only other variable which significantly influenced the risk of recurr ence. Conclusions - Analysis of several potential risk factors reveale d that recurrence was not related to the BIMI of the patient, the init ial treatment of the pneumothorax, nor to its size. Recurrence was mor e common in taller men and in women. Smoking cessation appeared to red uce the risk of recurrence. These findings are discussed in the contex t of the possible aetiology of spontaneous pneumothorax, recurrences, and the management thereof.