Cystic fibrosis transmembrane conductance regulator modulator therapy and lived experiences in South Africa: A mixed-methods study.

The sample is very small (37 surveys, 6 interviews) and drawn from a convenience sample of the 77 known CFTRm users in South Africa, so it is not representative of all CF patients. The design is cross-sectional and retrospective: participants recalled their pre-CFTRm state from memory. The authors explicitly note that contrast bias may make the pre-treatment period seem worse than it was, inflating the apparent size of change. There is no control group and no objective clinical data (lung function, sweat chloride, hospital records) to corroborate the self-reported improvements. Participants were recruited only through the private healthcare sector and the CF association network, so the sample is skewed toward those with medical insurance or the means to pay, limiting generalisability to the public-sector majority. The authors acknowledge a possible 'honeymoon period' effect: early experiences of a new, highly effective treatment may be perceived more positively than long-term experiences. No adverse events were reported, which the authors suggest may reflect under-reporting due to fear of losing access to therapy. Member checking was not conducted with interview participants, which the authors note as a limitation in confirmability.

The study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. However, the primary investigator is a physiotherapist with 30 years' experience in CF, the last author is a physician with over a decade in CF care, and all three senior authors are described as 'active advocates for CFTRm access in South Africa, creating potential for confirmation bias.' Student researchers conducted all interviews and initial coding to mitigate this.

Do not read the large reported improvements as a precise, unbiased measure of CFTRm's effect. This is a small, retrospective, self-reported study with no control group and no objective clinical data, and the authors themselves warn that participants may recall their pre-treatment state as worse than it truly was, which would inflate the apparent size of change. The direction of benefit is consistent, but the magnitude should be treated as a patient-reported impression rather than a validated effect size.