Outcome methods used in clinical studies of Chiari malformation Type I: a systematic review

Abstract

Object: Chiari malformation Type I (CM-I) is a common and often debilitating neurological disease. Efforts to improve treatment of CM-I are impeded by inconsistent and limited methods of evaluating clinical outcomes. To understand current approaches and lay a foundation for future research, the authors conducted a systematic review of the methods used in original published research articles to evaluate clinical outcomes in patients treated for CM-I.

Methods: The authors searched PubMed, Embase, the Cumulative Index to Nursing and Allied Health Literature, ClinicalTrials.gov , and Cochrane databases to identify publications between January 2003 and August 2013 that met the following criteria: 1) reported clinical outcomes in patients treated for CM-I; 2) were original research articles; 3) included at least 10 patients or, if a comparative study, at least 5 patients per group; and 4) were restricted to patients with CM-I.

Results: Among the 74 papers meeting inclusion criteria, there was wide variation in the outcome methods used. However, all approaches were broadly grouped into 3 categories: 1) "gestalt" impression of overall symptomatic improvement (n=45 papers); 2) postoperative change in specific signs or symptoms (n=20); or 3) results of various standardized assessment scales (n=22). Among standardized scales, 11 general function measures were used, compared with 6 disease-specific tools. Only 3 papers used scales validated in patients with CM-I. To facilitate a uniform comparison of these heterogeneous approaches, the authors appraised articles in multiple domains defined a priori as integral to reporting clinical outcomes in CM-I. Notably, only 7 articles incorporated patient-response instruments when reporting outcome, and only 22 articles explicitly assessed quality of life.

Conclusions: The methods used to evaluate clinical outcomes in CM-I are inconsistent and frequently not comparable, complicating efforts to analyze results across studies. Development, validation, and incorporation of a small number of disease-specific patient-based instruments will improve the quality of research and care of CM-I patients.

Keywords: CCOS = Chicago Chiari Outcome Scale; CM-I = Chiari malformation Type I; Chiari malformation Type I; JOA = Japanese Orthopaedic Association; VAS = visual analog scale; assessment tools; outcome methods; systematic review; treatment outcome.

Figures

FIG. 1.

A flow chart demonstrating the databases searched in the systematic review and the results retrieved. CINAHL = Cumulative Index to Nursing and Allied Health Literature.

FIG. 2.

A summary of the systems used to evaluate clinical outcomes in patients treated for CM-I. The Venn diagram demonstrates the approximate prevalence of each method as well as the overlap of various systems used in the same article. Figure is available in color online only.