Background: In this study, we aimed to evaluate the predictive value of the Haller index for recurrence risk in primary spontaneous pneumothorax patients.

Methods: Between January 2018 and December 2023, a total of 285 patients (260 males, 25 females; median age: 23 years; range, 17 to 35 years) with primary spontaneous pneumothorax who underwent thoracic computed tomography and followed for at least one year were retrospectively analyzed. The patients were divided into two groups as the non-recurrence group (n=170) and recurrence (n=115) group. The Haller index was calculated from computed tomography scans at presentation and its predictive value for recurrent pneumothorax was estimated.

Results: The median age was significantly higher in the nonrecurrence group than in the recurrence group (p<0.001). The median time to recurrence was two (IQR 1-3) months. The diagnostic validity of Haller index for predicting recurrence showed an area under the receiver operating characteristic of 0.824 (95% confidence interval [CI]: 0.775-0.866) (p<0.001). The optimal cut-off value of Haller index (>2.4) showed a sensitivity of 70.43% (95% CI: 61.2-78.6) and specificity of 76.47% (95% CI: 69.4-82.6).

Conclusion: A high Haller index is associated with increased recurrent pneumothorax risk in primary spontaneous pneumothorax patients. Traditionally used for pectus excavatum severity, incorporating Haller index in the management of these patients may help to identify high-risk patients and guide personalized management strategies.

Keywords : Haller index, primary spontaneous pneumothorax, recurrence