A group of researchers from Texas and Zimbabwe has lost a paper after they tried publishing it twice — first in the European Journal of Clinical Pharmacology, and then in the International Journal of Clinical Pharmacy.
Here’s the notice:
The International Journal of Clinical Pharmacy has been alerted to a case of duplicate publication in the following papers.
Int J Clin Pharm. 2012 Jun;34(3):432-8. Epub 2012 Jan 18. Use of antidepressants and the risk of type 2 diabetes
mellitus: a nested case–control study. Khoza S, Barner JC, Bohman TM, Rascati K, Lawson K, Wilson JP.Eur J Clin Pharmacol. 2011 Nov 26. [Epub ahead of print]. Use of antidepressant agents and the risk of type 2 diabetes. Khoza S, Barner JC, Bohman TM, Rascati K, Lawson K, Wilson JP.
The International Journal of Clinical Pharmacy is retracting the paper. We sincerely apologize to the scientific community.
The studies are indeed quite similar. The IJCP abstract:
Background Recent evidence from case reports, observational studies, and randomized trials suggests that long-term use of antidepressants increases the risk of developing diabetes. However, the nature of the relationship between antidepressants and diabetes remains unclear. Objective To determine whether there is an association between antidepressant use and the risk of developing type 2 diabetes mellitus. Methods A nested case–control study using the Texas Medicaid prescription claims database was conducted. Data were extracted for new users of either antidepressant agents (exposed) or benzodiazepines (unexposed) from January 1, 2002 through December 31, 2009. Patients aged 18–64 years without a history of diabetes were included in the cohort. The adjusted odds ratio (OR) and 95% confidence interval (CI) for the risk of diabetes associated with antidepressant exposure was computed using conditional logistic regression, controlling for demographic and clinical covariates. Main outcome measure Development of type 2 diabetes mellitus Results Among the total sample (N = 44,715), the majority were in the exposed (N = 35,552) vs. the unexposed (N = 9,163) group. A total of 2,943 cases of type 2 diabetes mellitus and 11,748 matched controls (1:4) were identified using risk-set sampling. Cases and controls were matched using age and gender. Antidepressant use was associated with an increase in the risk of (type-2) diabetes when compared to benzodiazepine use [Adjusted Odds Ratio (OR) = 1.512; 95% CI 1.345–1.700]. The association was observed with serotonin-norepinephrine reuptake inhibitors (OR = 1.742; 95% CI 1.472–2.060), tricyclic antidepressants (OR = 1.533; 95% CI 1.295–1.814), selective serotonin reuptake inhibitors (OR = 1.457; 95% CI 1.279–1.659), “Other” antidepressants (OR = 1.318; 95% CI 1.129–1.540). Conclusions Antidepressant use was associated with an increased risk of (type-2) diabetes. This association was observed for tricyclic antidepressants, serotonin-reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, and other antidepressants.
The EJCP abstract:
Purpose
To determine whether there is an association between antidepressant use and the risk of developing type 2 diabetes.
Methods
This study was a retrospective cohort analysis using the Texas Medicaid prescription claims database. Data were extracted for new users of either antidepressant agents (exposed) or benzodiazepines (unexposed) from January 1, 2002 through December 31, 2009. Patients aged 18–64 years without a prior history of diabetes were included. Cox proportional hazards regression was used to examine the association between diabetes incidence among exposed and unexposed groups, while controlling for demographic and clinical covariates.
Results
Among the total study population (N = 44,715), the majority were in the exposed (N = 35,552) versus the unexposed (N = 9,163) group. A total of 2,943 patients (6.6%) developed type 2 diabetes during the follow-up period. Antidepressant use was associated with an increase in the risk of diabetes when compared to benzodiazepine use (adjusted hazard ratio [HR] 1.558, 95% confidence interval [CI] 1.401–1.734). The association was observed with tricyclic antidepressants (TCAs; HR 1.759, 95% CI 1.517–2.040), serotonin–norepinephrine reuptake inhibitors (SNRIs; HR 1.566. 95% CI 1.351–1.816), selective serotonin reuptake inhibitors (SSRIs; HR 1.481, 95% CI 1.318–1.665), and “other” antidepressants (HR 1.376; 95% CI 1.198–1.581).
Conclusions
The results of this study suggest that antidepressant use is associated with an increased risk of diabetes. This association was observed with use of TCAs, SNRIs, SSRIs, and “other” antidepressants.
Both journals, we should note, are Springer publications. We’ve contacted corresponding author Star Khoza — who seems to have done her PhD thesis on the subject of the papers at the University of Texas at Austin before moving to Zimbabwe — for comment, and will update with anything we learn.
Duplication retractions — sometimes referred to, somewhat inelegantly, as “self-plagiarism” — can spark heated debate here on Retraction Watch. There are copyright issues, which some scientists say make them do unnecessary rewrites of their own words. But a more important point, and of significance in this case, is that review articles and meta-analyses can end up counting the same study twice, inflating the results and skewing conclusions.