Roche and GSK will carry out a meta-analysis of liver function data from trials of orlistat to establish whether there is any indication of liver toxicity. The motivation is a cumulative assessment of drug-induced liver injury (DILI) conducted by the FDA following spontaneous reports of liver toxicity in people taking Xenical or Alli.

Inclusion Criteria:

1. The trial must be randomized and placebo-controlled
2. The orlistat dose must be 60mg or 120mg
3. Data on ALT or BIL must be available
4. The nominal treatment period must be 16 weeks or longer

Exclusion Criteria:

1. If cross-over trials are found, data from other than the first period will be excluded.

All clinical trials found by search procedure:

1. In-house trial repositories at GSK and Roche
2. EMBASE (which includes MEDLINE) using the terms "orlistat", "Xenical" or "Alli", with "placebo" and "clinical trial"
3. Recently published meta-analyses found by the search will also be searched for relevant trials