Primary and Secondary Pneumothoraces Compared

The table below provides a comparison between primary and secondary pneumothoraces.

Table: Comparison of primary and secondary pneumothoraces

Primary Secondary
Peak incidence age (years) 20-30 60-70
Male:frmale ratio 6:1 3:1
Aetiology Ruptured sub-pleural bleb Various
Proportion of all spontaneous pneumothoraces 80-90% 10-20%
1 year recurrence rate (without pleurodesis) 25% Higher but dependent on underlying condition