RETRACTED: Homocysteine as a predictive factor for hip fracture in elderly women with Parkinson's disease.
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).

This article is being retracted at the request of the Editor in Chief because of the stated concerns listed below. The article was accepted for publication by a previous editor and editorial board nearly 15 years ago, at a time when submissions and documentation were in paper form, prior to the transition of The American Journal of Medicine to a digital submission and review process. The records, including the original manuscript and peer reviewers' comments, are no longer extant and consequently we are unable to review the comments of the peer reviewers and the editors involved at that time. Nevertheless, the allegations of Grey et al. (as detailed in their Letter of Concern, published in the March 2018 issue of AJM, Volume 131, Issue 3, pages e107–e108; DOI: 10.1016/j.amjmed.2017.10.009) seem valid. A response by the Editor-in-Chief was also published in that issue.

Therefore, given the documentation of Grey et al, the journal has concluded that this article should be considered as likely fraudulent and should not be quoted in the scientific literature in support of its conclusions.

The article is severely compromised by wide-ranging and serious concerns about governance, ethics, authorship, implausible study conduct, implausible workload, discrepant participant numbers and treatment groups, impossible data, implausible data, implausible outcome data and discrepant methodology. The concerns are detailed in the afore-referenced letter of concern and can be summarized as follows:

• It is stated that the study was approved by the Human Investigation Committee of the Futase Social Insurance Hospital, yet Futase Hospital did not have an ethics committee until 2010.

• Given the size of the hospital and volume of clinics undertaken, it is highly unlikely that the stated number of participants could have been recruited within 3 months, or followed up as reported.

• There are inconsistencies in the reported data. In Table 1 the mean ages of participants by quartiles of plasma homocysteine are 69.0, 70.6, 71.9, and 72.6 years. The corresponding mean years since menopause are 13.7, 14.6, 15.2, and 16.2 years, meaning that the average age of menopause is 55–57 years, implausibly older than the expected value of 50 years. The plasma homocysteine data in quartile 1 are incorrect. Among 50 women with a range of 6.1-9.0 μmol/L, the reported mean (standard deviation), 7.1 (2.5) μmol/L, is not possible.

• In Table 3 the rate of hip fractures in the cohort (72 per 1000 patient-years) is implausibly high, being at least 3 to 4 times that reported in large observational studies of PD. The 51 incident hip fractures in 50 women in quartile 4 represents an astonishing hip fracture incidence of 227 per 1000 patient-years, yet only 6 women (3%) in this quartile were lost to follow-up (Table 1), and none was apparently treated with medications known to reduce fracture risk. The reported incident rates for hip fracture are incorrect.

We have attempted to contact the authors regarding these concerns and have received no response. We are therefore retracting this article since the evidence presented indicates that there has been scientific misconduct.

Joseph S. Alpert, MD

Professor of Medicine, University of Arizona College of Medicine, Tucson, Arizona; Editor in Chief, The American Journal of Medicine
Sato
Yoshihiro
Y
Department of Neurology, Mitate Hospital, Tagawa, Japan. y-sato@ktarn.or.jp
Iwamoto
Jun
J
Kanoko
Tomohiro
T
Satoh
Kei
K
D000058:Accidental Falls / Q000706:statistics & numerical data; D000368:Aged; D000978:Antiparkinson Agents / Q000009:adverse effects* / Q000627:therapeutic use; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005598:Fractures, Spontaneous / Q000453:epidemiology / Q000209:etiology; D006620:Hip Fractures / Q000453:epidemiology* / Q000209:etiology; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000139:chemically induced / Q000150:complications / Q000453:epidemiology*; D007103:Immobilization / Q000009:adverse effects; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D007980:Levodopa / Q000009:adverse effects* / Q000627:therapeutic use; D010024:Osteoporosis / Q000209:etiology; D010300:Parkinson Disease / Q000097:blood / Q000150:complications* / Q000188:drug therapy; D016016:Proportional Hazards Models; D012307:Risk Factors
D000978:Antiparkinson Agents; D006710:Homocysteine; D007980:Levodopa