Individual patient data

The main aims of data checking procedures are to ensure the accuracy of data, integrity of randomization and completeness of follow up. For any one trial the results of all the data checks should be considered together to build up an overall picture of that trial and any associated problems. Where there are concerns about the data supplied, these should be brought to the attention of the trialist and sympathetic efforts made to resolve them. Range and consistency checks should be carried out...

Example of an IPD metaanalysis Postoperative radiotherapy in nonsmallcell lung cancer

Introduction Worldwide, over half a million new cases of lung cancer are diagnosed each year 58 and it is the leading cause of cancer deaths. Surgery is the treatment of choice for non-small-cell lung cancer (NSCLC), and around one fifth of tumours are suitable for potentially curative resection 59 . However, even for patients with apparently completely resected disease, survival rates are disappointing - around 40 per cent at two years. In an effort to improve both local control and survival,...

Barriers to taking part in trials

Although many patients are eligible to enter trials of cancer therapy, accrual rates are low and it is estimated that on average around 5 per cent of UK patients 1 and 3 per cent of US patients 2 take part. Trials generally rely on a minority of clinicians who have a particular interest in research and who recruit the majority of patients. However, even among highly committed doctors, accrual rates can be low. For example, a survey of members of the research-oriented US Eastern Cooperative...

Alternative randomization procedures

Zelen's central thesis 10 was that patients receiving exactly the same treatment within a trial that they would have received outside of a trial did not necessarily need to be aware that they were in a trial. He therefore proposed what became known as Zelen's single consent design, which is illustrated in Fig. 4.2. In this design, patients who are eligible for the trial, and fit to receive any of the treatments which maybe allocated, are randomized without their consent. Those patients Fig. 4.1...