Search Strategy
In this review, we searched for prospective controlled trials determining the efficacy of the oral adsorbent AST-120 in delaying the decline of renal function among CKD patients, regardless of etiology. In terms of outcomes, articles with any one of the following outcomes were deemed appropriate for inclusion in the review: rate of serum creatinine increase, rate of deterioration of creatinine clearance, incidence of dialysis, incidence of kidney transplantation, adverse events or mortality rate.
We searched for articles in PubMed including MedLine, Clinicaltrials.gov, and Cochrane databases. Search terms were based on the components of the research question. Keywords used were as follows: “chronic kidney disease,” serving as the concept for the population, and “oral adsorbent,” serving as the concept for the intervention. In the process of using the databases’ search engines, each of these concepts were expanded using Boolean operators to maximize search sensitivity. The term “chronic kidney disease” were combined with its alternative terms, including its MeSH terms, using the “OR” Boolean operator. The term “oral adsorbent” were likewise combined with its alternative term (“Kremezin”) and MeSH counterpart (“AST-120”). These expanded concepts for the population and intervention were intersected using the “AND” Boolean operator to narrow down the search. The retrieved articles were further filtered to only include prospective controlled trials. Each of the abstracts of the articles were examined to assess appropriateness for inclusion in the meta-analysis. Articles that did not reflect the research question, as well as studies that were not prospective controlled trials, were excluded.
Specifically, the search entailed the use of the following terms: (“chronic kidney disease”[All Fields] OR “chronic renal disease”[All Fields] OR “chronic renal failure”[All Fields] OR “chronic kidney failure”[All Fields] OR “chronic renal insufficiency”[MeSH Terms]) AND (“oral adsorbent”[All Fields] OR “Kremezin”[All Fields] OR “AST-120”[MeSH Terms])