Foundayo trials: ATTAIN, ACHIEVE and the capsule-to-tablet bridge

ATTAIN and ACHIEVE answer different questions

ATTAIN studies look at weight management. ACHIEVE studies look at type 2 diabetes treatment. A trial in people without diabetes tells you little about glucose results in someone on insulin. A glucose-lowering trial is often too short or too small to show long-term prevention of heart attacks and strokes.

The UK SmPC names each study and the people who took part. Read the entry criteria and background treatments before you compare results. A result in newly diagnosed diabetes may not describe someone with long-standing disease who takes several glucose-lowering medicines.

UK tablets differ from the trial capsules

The trials in the UK label used hard capsules. UK pharmacies dispense film-coated tablets in different milligram strengths. The label explains how exposure matches between the two forms. This is why a 17.2 mg tablet and a 36 mg capsule appear side by side in the evidence.

Whenever someone quotes a trial dose, they should say which form it refers to. The match between capsule and tablet is for prescribers. Do not swap or convert doses yourself. A trial capsule is also a different product from the pack your UK pharmacy hands you.

Ask what question an average answers

An intention-to-treat analysis counts every participant in the group they were assigned to. This keeps the benefit of randomisation. Other analyses estimate the result if everyone had kept taking treatment as planned. Missing data, people stopping early and rescue treatments affect both methods, and the statistical plan decides how those events count.

Look past the biggest number. Ask which question each analysis answers and how close that question sits to your own decision. If you are deciding whether to start, the chance of stopping because of side effects matters as much as results in people who carried on.

Where a single trial runs out

A moderate-sized study is too small to measure rare harms well. A short study says nothing about safety or results over decades. People with excluded conditions remain an open question. These limits leave the study valid. They mark the edges of what it shows.

Look for manufacturer funding, trial registration, methods and publication status. An independent critique helps with interpretation, but independence alone does not make a claim right. The fair approach is to link the original evidence, describe the uncertainty and avoid ranking medicines on headline numbers from unmatched trials.

An outcome chosen before a trial starts carries more weight than a pattern spotted afterwards. Exploratory subgroup results raise useful questions, but small groups are prone to chance differences. A careful summary names the primary endpoint and labels exploratory results as exploratory.

Questions for your appointment

Check the ATTAIN or ACHIEVE study name, the capsule dose, the matching tablet strength and who took part. Ask whether any comparison with another medicine came from a direct randomised trial or was pieced together from separate trials.