Comparative effectiveness of lansoprazole and omeprazole for the prevention of gastrointestinal bleeding and malignancy

Date of ISAC Approval: 
29/06/2016
Lay Summary: 
Proton-pump inhibitor (PPI) drugs, predominantly lansoprazole and omeprazole, are a very commonly used class of drugs prescribed for the treatment of gastric ulceration, reflux, as prophylaxis for people at risk of gastric ulceration and as part of triple therapy to eradicate H. Pylori infection. Gastric ulceration, H. Pylori infection and gastro-oesophageal reflux are risk factors for the development of upper gastric bleeding and malignancy. Although these drugs are so commonly used, and often for many years, there have been no long-term clinical trials investigating the relative efficacy of these drugs. In the UK the primary choice of PPI by GP prescribers has changed at various times and has been dictated by local guidelines related to cost rather than characteristics of the patients which may act as confounders between exposure and outcome. Therefore this relative lack of confounding by patient characteristics provides an excellent opportunity to compare the outcomes of people using these medications in real clinical practice.
Technical Summary: 
The overall objective of this study is to compare the rates of upper gastrointestinal bleed and malignancy among users of lansoprazole and omeprazole. New users of each drug will be selected from CPRD and in the primary analysis, outcomes recorded in the CPRD using Read codes will be identified. Initially descriptive analyses will be performed to ascertain how similar the comparison groups are. Then the rate of outcomes will be compared between the two groups using Cox regression adjusting for a range of possible confounding factors. The two outcomes of upper gastrointestinal bleed and malignancy will be analysed separately. As a sensitivity analysis, linked HES and ONS mortality data will be used to identify any additional outcomes requiring hospitalisation or resulting in death not recorded elsewhere in CPRD.
Health Outcomes to be Measured: 
Upper gastrointestinal bleed and malignancy among users of lansoprazole and omeprazole
Collaborators: 

Ian Douglas - Chief Investigator - London School of Hygiene & Tropical Medicine (LSHTM)
Fabio Cassiodoro Veiga Scarduelli - Collaborator - London School of Hygiene & Tropical Medicine (LSHTM)
Ian Douglas - Corresponding Applicant - London School of Hygiene & Tropical Medicine (LSHTM)
Dr Laurie Tomlinson - Collaborator - London School of Hygiene & Tropical Medicine (LSHTM)
Masao Iwagami - Collaborator - University of Tsukuba

Linkages: 
HES Admitted;ONS;Patient IMD;Practice IMD (Standard)