When one paper contains two trials, do not average the hours

Research Methods

When one paper contains two trials, do not average the hours

The afamelanotide report gives a 6-month United States result and a 9-month European result. They are not one pooled afternoon.

August 28, 2026 1 min read Methods Afamelanotide

Some papers report two protocols under one title. The afamelanotide trials in erythropoietic protoporphyria did that. Both used a 16 mg subcutaneous implant or placebo. They did not use the same number of implants, the same length of observation, or the same median hours of pain-free sun.

Do not pool by eye

The United States median at 6 months was 69.4 hours versus 40.8. The European median at 9 months was 6.0 hours versus 0.8. Averaging 69.4 and 6.0 produces a number neither trial measured. A methods note keeps each median next to its country, its duration, and its implant count.

Registries help

NCT01605136 and NCT00979745 are the registrations named with the paper. If a sentence cannot be tied to one of them, it is probably a blend. Blends are how a careful trial becomes a looser claim.

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