| Автор | HORVITZ-LENNON, MARCELA |
| Автор | JAMES OʼMALLEY, A. |
| Автор | FRANK, RICHARD G. |
| Автор | NORMAND, SHARON-LISE T. |
| Дата выпуска | 2005 |
| dc.description | Background. Drop-out, often accompanied by treatment non-compliance, is common in psychiatric trials. Methodologists have criticized the use of a traditional intention-to-treat (ITT) approach in such cases, and have proposed alternative methods. We set out to describe and assess methods for estimation of a treatment effect when the trial is ‘broken’.Method. We describe a stratified method of moments (SMOM) estimator that assesses treatment effects on subjects who are willing to comply with all the treatments under study. A simulation study and a re-analysis of data from an antipsychotics trial are used to compare SMOM to ITT, as-treated, and adequate estimators.Results. The new estimator retains good statistical properties under different levels of non-compliance and drop-out mechanisms. The re-analysis indicates that SMOM yields more precise results.Conclusions. Although the traditional ITT approach provides a valid method to estimate treatment effects, it can be biased in the presence of treatment non-compliance and drop-out. It is critical that researchers move beyond traditional approaches when trials are broken. A key first step is to consider non-compliance and drop-out as two independent phenomena, tracking and reporting rates separately. |
| Издатель | Cambridge University Press |
| Название | Improving traditional intention-to-treat analyses: a new approachPresented in part at the 15th International Conference on Mental Health Services Research organized by the National Institute of Mental Health, Washington, DC, USA, 2 April 2002. This work was completed while Dr Horvitz-Lennon was Instructor, Department of Psychiatry, The Cambridge Hospital, Cambridge, MA, and Harvard Medical School, Boston, MA, USA. |
| DOI | 10.1017/S0033291705004551 |
| Electronic ISSN | 1469-8978 |
| Print ISSN | 0033-2917 |
| Журнал | Psychological Medicine |
| Том | 35 |
| Первая страница | 961 |
| Последняя страница | 970 |
| Аффилиация | HORVITZ-LENNON MARCELA; University of Pittsburgh; University of Pittsburgh Medical School |
| Аффилиация | JAMES OʼMALLEY A.; Harvard Medical School |
| Аффилиация | FRANK RICHARD G.; Harvard Medical School |
| Аффилиация | NORMAND SHARON-LISE T.; Harvard Medical School; Harvard School of Public Health |
| Выпуск | 7 |
