This article has been retracted: please see Elsevier Policy on Article Withdrawal (withdrawalpolicy).

This article is being retracted at the request of the Editor in Chief because of the stated concerns listed below. The author was contacted to provide information related to concerns about governance, ethical oversight, authorship and location of study. As this information was not fully provided and the response received not sufficient, the concern with regard to the integrity of the publication remains and the article will be retracted.

In addition, the Research Integrity Office at Imperial College London was contacted for comment and responded that they were not able to locate information related to the clinical trial to investigate further. However, Imperial College noted that the article was published several years after the author had left Royal Postgraduate Medical School and it is unlikely that the author would have been solely responsible for the research reported in this single-authored paper. They noted that concerns raised regarding the article appear to be well-founded.

Research governance

• No details of the source(s) of funding were provided for the 4-year clinical trial.

• Study location was not specified in the article.

Ethics

• The name of the ethics committee which approved the study was not reported.

Authorship

• Discrepancies between author’s reported institutional affiliations and the timing of his employment at that institution, such that he was the sole author on a publication that describes a 4-year clinical trial published in 1998 yet had left the institution at which the work was said to have been conducted 4 years earlier.

Productivity

• Only 1 researcher for the conduct of complicated and labour-intensive 4-year clinical trial.

Research conduct

• Dates during which the studies took place are not reported.

• Recruitment and follow-up workload seem implausible for a single investigator.

Statistics and data

• Baseline summary data in randomized groups seem implausibly similar.

• There was an implausibly high frequency of identical summary data in randomized groups.

• Variances in several variables were implausibly small.

• There were discrepancies between reported whole group mean values and those calculated from reported subgroup data.

• Fracture data contains errors and outcomes are implausible.

• Fractures are implausibly more frequent at vertebral than non-vertebral sites.

• Implausible rates of height loss are reported.