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Background: The assessment of treatment success in clinical trials when multiple (repeated) doses (courses) are involved is quite common, for example, in the case of infertility treatment with assisted reproductive technology (ART), and medical abortion using misoprostol alone or in combination with mifepristone. Under these or similar circumstances, most researchers assess success using binomial proportions after a certain number of consecutive doses, and some have used survival analysis. In this paper we discuss the main problems in using binomial proportions to summarize (the overall) efficacy after two or more consecutive doses of the relevant treatment, particularly for the case of misoprostol in medical abortion studies. We later discuss why the survival analysis is best suited under these circumstances, and illustrate this by using simulated data.Methods: The formulas required for the binomial proportion and survival analysis (without and with competing risks) approaches are summarized and analytically compared. Additionally, numerical results are computed and compared between the two approaches, for several theoretical scenarios.Results: The main conceptual limitations of the binomial proportion approach are identified and discussed, caused mainly by the presence of censoring and competing risks, and it is demonstrated how survival analysis can solve these problems. In general, the binomial proportion approach tends to underestimate the "real" success rate, and tends to overestimate the corresponding standard error.Conclusions: Depending on the rates of censored observations or competing events between repeated doses of the treatment, the bias of the binomial proportion approach as compared to the survival analysis approaches varies; however, the use of the binomial approach is unjustified as the survival analysis options are well known and available in multiple statistical packages. Our conclusions also apply to other situations where success is estimated after multiple (repeated) doses (courses) of the treatment. [ABSTRACT FROM AUTHOR]

Background: Intermediate outcomes are common and typically on the causal pathway to the final outcome. Some examples include noncompliance, missing data, and truncation by death like pregnancy (e.g. when the trial intervention is given to non-pregnant women and the final outcome is preeclampsia, defined only on pregnant women). The intention-to-treat approach does not account properly for them, and more appropriate alternative approaches like principal stratification are not yet widely known. The purposes of this study are to inform researchers that the intention-to-treat approach unfortunately does not fit all problems we face in experimental research, to introduce the principal stratification approach for dealing with intermediate outcomes, and to illustrate its application to a trial of long term calcium supplementation in women at high risk of preeclampsia. Methods: Principal stratification and related concepts are introduced. Two ways for estimating causal effects are discussed and their application is illustrated using the calcium trial, where noncompliance and pregnancy are considered as intermediate outcomes, and preeclampsia is the main final outcome. Results: The limitations of traditional approaches and methods for dealing with intermediate outcomes are demonstrated. The steps, assumptions and required calculations involved in the application of the principal stratification approach are discussed in detail in the case of our calcium trial. Conclusions: The intention-to-treat approach is a very sound one but unfortunately it does not fit all problems we find in randomized clinical trials; this is particularly the case for intermediate outcomes, where alternative approaches like principal stratification should be considered. [ABSTRACT FROM AUTHOR]

Objectives To assess the side effects unrelated to disease activity and the acceptability of combined oral contraceptives (COCs), progestin-only pills (POPs) and copper-releasing intrauterine devices (IUDs) in women with systemic lupus erythematosus (SLE). Study design A randomized clinical trial including 162 women with SLE, assigned to COC (n= 54), POP (n= 54) or IUD (n= 54). Follow-up visits were conducted after 1, 2, 3, 6, 9 and 12 months of treatment to monitor the presence of symptoms, changes in body weight and blood pressure as well as the development of health problems other than those relating to lupus. Reasons for discontinuation and satisfaction with the use of the assigned method were recorded at the end of treatment. Statistical analysis included descriptive statistics, repeated measure analyses and Kaplan-Meier curves. Results Significantly different discontinuation rates due to any reason [35%, 55%, 29% (p<0.01)] or nonmedical reasons [(11%, 31%, 4% (p<0.05)] were observed among the COC, POP and IUD groups. Nausea was most frequent among COC users, dysmenorrhea among IUD users and acne and hirsutism among POP users. Mean blood pressures remained unchanged. Mild increases in body weight were observed over time in all treatment groups. Most women were satisfied with the use of the assigned contraceptive method. Conclusions Oral contraceptives and IUD are acceptable birth control methods for patients with lupus, when counseling and specialized health attention are provided; however, the acceptability of POP appears to be inferior. Side effects unrelated to lupus disease activity are not frequent reasons to discontinue the contraceptive methods. Implications This study delves into an area that has not been explored among patients with lupus. Our findings on the associated side effects and reasons for discontinuing COCs, POPs or copper-bearing IUDs may be useful in improving contraceptive counseling for women with lupus. Furthermore, they also heighten our knowledge on the reasons that may preclude the widespread use of effective contraceptives among lupus patients. [ABSTRACT FROM AUTHOR]

Background: The effects of estrogen-containing contraceptives on disease activity in women with systemic lupus erythematosus have not been determined. Methods: We conducted a single-blind clinical trial involving 162 women with systemic lupus erythematosus who were randomly assigned to combined oral contraceptives, a progestin-only pill, or a copper intrauterine device (IUD). Disease activity was assessed at 0, 1, 2, 3, 6, 9, and 12 months according to the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). The primary outcome was global disease activity, which we estimated by measuring the area under the SLEDAI curve. Secondary outcomes included the maximum SLEDAI score, change in SLEDAI score, incidence of lupus flares, median time to first flare, systemic lupus erythematosus treatment, and adverse events. The results were analyzed by the intention-to-treat method. Results: At baseline, all demographic features and disease characteristics were similar in the three groups. The mean (±SD) SLEDAI score was 6.1±5.6 in the group assigned to combined oral contraceptives, 6.4±4.6 in the group assigned to the progestin-only pill, and 5.0±5.3 in the group assigned to the IUD (54 patients in each group) (P=0.36). Disease activity remained mild and stable in all groups throughout the trial. There were no significant differences among the groups during the trial in global or maximum disease activity, incidence or probability of flares, or medication use. The median time to the first flare was three months in all groups. Thromboses occurred in four patients (two in each of the two groups receiving hormones), and severe infections were more frequent in the IUD group. One patient receiving combined oral contraceptives died from amoxicillin-related severe neutropenia. Conclusions: Global disease activity, maximum SLEDAI score, incidence of flares, time to first flare, and incidence of adverse events were similar among women with systemic lupus erythematosus, irrespective of the type of contraceptive they were using. N Engl J Med 2005;353:2539-49. [ABSTRACT FROM AUTHOR]