Data Extraction A form was developed to aid data extraction. The first part of the form was a checklist comprised of items contained in the CONSORT Statements, including those items specific to herbs found in the CONSORT Statement for Herbal Intervention (14). Using the CONSORT Statements provided a good starting point for the data extraction form as they consist of lists of criteria deemed to be important in the reporting of an RCT such that a reader will understand how a trial was conducted and be able to assess the validity of results. Additionally, the CONSORT Statements provide detailed explanation of the meaning of the criteria used, which would aid the accurate extraction of data (12,14,15). Following the itemized extraction portion, the data extraction form contained an area for recording additional items found in instruments but not contained in the CONSORT Statements. These were termed miscellaneous items. In the second section of the data extraction form, the articles were categorized by type of instrument (checklist, rating scale, numeric scale, combination of checklist and scale) or as a guidance document. The term guidance document was adapted from a previous publication and in this project was intended to capture articles that described how to report an RCT or discussed the importance of assessing publication quality and provided example items for consideration (7). The method used to develop the instrument, any process used for validation and provision of instructions for use, were also recorded. Two investigators (A.M.W. and L.L.) independently completed data extraction for all articles. Disagreements were resolved by the third investigator (T.J.). Analysis Data were analyzed using descriptive statistics. The identified instruments were separated into categories based on whether they were a type of instrument (check- list, numeric scale, rating scale, combination checklist and scale) or a guidance document. A list of items contained in instruments was compiled and the number of instru- ments that included each item was tabulated. Miscellaneous items were also tabulated. Methods of development and validation were examined to identify the most common processes used. References cited as a source of instrument development were reviewed to determine if the same pool of instruments were used as a basis for instrument development. Results Article Retrieval and Relevance Assessment Online database searches and hand searching of investigators files, websites, textbooks and reference eCAM 2009;6(4) 443 lists identified 4442 citations (Fig. 1). Of these, 4032 citations were excluded after initial review indicated they were not pertinent to the project. Review of the remaining 410 abstracts identified a total of 29 potentially relevant articles, 16 of which met the inclusion criteria (14,16–30). Of the 16 instruments 6 were checklists, 3 combinations of a scale and a checklist, 3 rating scales and 4 numeric scales. No guidance documents specific to NHPs were identified. Data Extraction Items In the 16 instruments developed specifically for use with NHPs, the most common items included randomization sequence generation (100%), blinding (100%), allocation concealment (75%), participant flow (75%) and baseline data (50%) (Fig. 2). Nine of these instruments included at least one item to appraise the identity or content of the NHP (14,17,18,20–22,25,29,30). Only 4 of the 16 instruments included items pertaining to the general- izability of the results (14,18,20,27). Twelve items not found in the CONSORT Statements were extracted from the instruments for NHPs and recorded as miscellaneous items (Table 1). Instrument Development, Validation and Guidelines for Use A description of the method used to develop the instrument was provided for a total of 12 of the 16 instruments (75%). Eleven of the instruments that reported method of development were adapted or modified from one or more existing instruments and one was developed as a result of a discussion of experts. The most common references cited as sources for modification/adaptation for new instrument development are listed in Table 2. None of the 16 instruments stated that they had been validated. Instructions for using critical appraisal instru- ments were included with four of the identified instru- ments (14,18,21,25). Discussion As anticipated, there was a paucity of instruments for the critical appraisal of RCTs evaluating the efficacy of NHPs. The CONSORT Statement for Herbal Interventions (14) most closely addressed the four components (quality of methods, details of the identity and content of NHP tested, generalizability of results and instructions for use) felt to be important in such an instrument. However, the CONSORT Statement for Herbal Interventions had two limitations. It was designed for use exclusively with herbal medicines, and