Reply of the Authors

Abstract

We appreciate the comments by Kurt T. Barnhart, M.S.C.E., regarding our manuscript (1Alleyassin A. Khademi A. Aghahosseini M. Safdarian L. Badenoosh B. Hamed E.A. Comparison of success rates in the medical management of ectopic pregnancy with single-dose and multiple-dose administration of methotrexate: a prospective, randomized clinical trial.Fertil Steril. 2006; 85: 1661-1666Abstract Full Text Full Text PDF PubMed Scopus (93) Google Scholar). The article we published was a preliminary, randomized clinical trial (RCT) about the investigation of effectiveness of two methods of methotrexate (MTX) administration for ectopic pregnancy (EP). As Dr. Barnhart mentioned, the crude overall success rate for women managed with the multiple-dose protocol was 92.7% whereas the crude overall success rate for patients managed with the single-dose therapy was 88.1% (2Barnhart K.T. Gosman G. Ashby R. Sammel M. The medical management of ectopic pregnancy: a meta-analysis comparing “single dose” and “multidose” regimens.Obstet Gynecol. 2003; 101: 778-784Crossref PubMed Scopus (294) Google Scholar). Based on these findings, we emphasized that single-dose therapy could be a first-line of treatment in only selected patients. This interpretation does not force us to use single-dose MTX generally. The finding of our study only shows that practitioners can choose the single-dose method for selected patients. As Dr. Barnhart mentioned, we can decrease the failure rate associated with medical management of EP by giving more than one dose of MTX (with a potential repeat dose 1 week later). In our study, all six of the patients in whom single-dose treatment had failed did respond to a second dose (1Alleyassin A. Khademi A. Aghahosseini M. Safdarian L. Badenoosh B. Hamed E.A. Comparison of success rates in the medical management of ectopic pregnancy with single-dose and multiple-dose administration of methotrexate: a prospective, randomized clinical trial.Fertil Steril. 2006; 85: 1661-1666Abstract Full Text Full Text PDF PubMed Scopus (93) Google Scholar). However, we need to ask whether it is appropriate to offer multiple-dose therapy to all patients when we can handle patients by one dose and offer a second dose for the failed cases. These findings suggest that finding a statistically significant difference between the multiple-dose and single-dose method should not preclude offering the single-dose method to special patients. We emphasized that our findings do not mean that the two methods are the same (type II error). In our opinion, the difference in comments is related to management of treatment for total patients versus a single patient. We know that all RCTs do not provide level І evidence, and this was true for our study as well. There are many factors that interfere in decision making that are not concluded in this study. Other RCTs considering factors such as long-term side effects and cost are needed to confirm or deny the value of using single-dose MTX therapy in EP in general. Statistical power to detect differencesFertility and SterilityVol. 87Issue 6PreviewEvidence-based medicine should affect the way we practice. A properly planned and executed clinical trial is a powerful technique for assessing the effectiveness of an intervention (1). Level I evidence is based on the conclusions of a well-conducted, randomized clinical trial (RCT). However, all RCTs do not provide level I evidence. One of the most common, and perhaps dangerous, errors we make when interpreting the literature is a type 2 error: not rejecting the null hypothesis that two therapies are different when in fact they are. Full-Text PDF