A systematic review collects all relevant studies on a subject, integrates findings, and allows readers to do their own assessments based on all available evidence. Inferences from systematic reviews stand in sharp contrast to picking and choosing individual studies from which to make decisions such as treatment.
Mild cognitive impairment (MCI) has been controversial both in terms of clinical validity and treatment. Many physicians choose to treat patients they diagnose with MCI with cholinesterase inhibitors.
Raschetti and colleagues did a systematic review of randomized, placebo-controlled MCI trials of the marketed cholinesterase inhibitors. They identified eight such trials, including two in which data were unavailable. The authors neatly summarized characteristics and outcomes of the trials and made a number of observations:
1. Although the trials used the Petersen or Mayo Clinic criteria for MCI, each trial operationalized the criteria differently.
2. The outcomes and scales used, especially cognitive scales, varied widely beyond the...