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Search strategy and evidence selection

Search strategy and evidence selection

Search strategy

The strategy reflects the nature of the MIB assessments as rapid evidence reviews; the search strategy was pragmatic in order to retrieve a volume of records manageable within the timescales of the project. The strategy was developed for MEDLINE (Ovid interface). The search comprised 2 concepts:

  • The intervention. Search lines 1 to 5. This is captured by text words and subject headings to denote ultrasonics; this appears to be the key aspect of OSCAR 3 which distinguishes it from other devices for prosthesis revision.

  • The population. Search lines 6 to 11. This concept captures cement removal and prosthesis revision using text words and subject headings.

Two additional, focused search lines (13 and 14) for the brand name of the device and ultrasonics in the context of hip, knee, shoulder or elbow prostheses were also used. These were designed to capture any records that may have been missed by the 2-concept approach.

As is standard in searches for MIB evaluations, non-English language publications were excluded from the search results (search line 19). The strategy also excluded studies published in dental journals (search line 17) in order to increase precision by excluding evidence on the removal of dental cement.

The strategy was limited to studies published from 1990 to current; this reflects the year Orthosonics was formed.

The final strategy was peer-reviewed by an independent information specialist. The MEDLINE strategy was translated appropriately for other databases.

The following databases were searched:

  • Cochrane Central Register of Controlled Trials (Cochrane Library, Wiley)

  • Cochrane Database of Systematic Reviews (Cochrane Library, Wiley)

  • Database of Abstracts of Reviews of Effects (Cochrane Library, Wiley)

  • Embase (OvidSP)

  • Health Technology Assessment Database (Cochrane Library, Wiley)

  • MEDLINE and MEDLINE in Process (OvidSP)

  • NHS Economic Evaluation Database (Cochrane Library, Wiley).

Evidence selection

A total of 1437 records were retrieved from the literature search. After de-duplication, 920 remained. An initial 140 records were excluded at first pass as obviously irrelevant topics. This left 780 records remaining for assessment.

Records were sifted independently by 2 researchers. Any disagreements were discussed and, if agreement was not reached, were settled by a third independent arbiter. The first sift removed 759 records based on the following exclusion criteria:

  • articles of poor relevance against search terms

  • publication types that were out of scope

  • non-English language studies

  • conference abstracts

  • review articles and protocols (for example, Cochrane review protocols).

Full articles were retrieved for the remaining 21 studies with full text assessment undertaken at second sift to identify relevant primary research addressing the specific use of the medical technology, within the defined indication under review. As it was immediately apparent that there was a paucity of data concerning the technology, all primary studies that included the term OSCAR were included and considered on an individual basis. This included in vitro studies, ex vivo studies, and studies in animals. In the second sift, 16 papers were therefore excluded because they did not concern the OSCAR system. Of the excluded papers at this sift, 1 concerned a dental ultrasound system, 4 concerned the Ultra-Drive 3 Ultrasonic Revision System (Biomet Orthopedics), 3 concerned an older system developed by Osseous Technologies and 8 concerned prototype ultrasound systems or the system was not specified. Only 1 excluded study, by Gardiner et al. (1993), had outcomes relevant to patients and healthcare services.