Table 1

Description of the main methodological characteristics of the PACHA study in four steps

StepStudy design and objectiveStudy samplesMeasures, analysis and outcomesExpected results
1Systematic literature review to identify indicators of the appropriateness of oral anticoagulant prescriptionsGuidelines on: (1) clinical situations for which a prescription of oral anticoagulants is indicated or contraindicated; (2) the appropriate use of oral anticoagulants for validated clinical indicationsCritical appraisal of guidelines; definition of a panel of indicators identified from guidelines whose quality was judged sufficiently goodIdentification of a panel of indicators covering misuse, underuse and overuse of oral anticoagulants
2Delphi consensus method to assess the potential utility and operational implementation of the indicatorsExperts with clinical expertise about the targeted clinical situations and prescriptions of oral anticoagulantsRating of the potential utility and operational implementation (in terms of frequency and severity); selection of indicators for which at least 8 out of 10 experts judged them both useful and implementableValidation of the final list of indicators and their order of implementation from the hospital information system
3Prospective phase during which techniques of medical data search will be used to implement the selected indicators from the hospital information systemSamples of hospital stays of patients cared at Bordeaux University or Georges Pompidou European hospitals in 2015 for targeted clinical situations or having had a prescription of oral anticoagulants (defined as type 1 samples; one sample per indicator)Extraction and integration of all the concepts of interest from the hospital information system into the i2b2 data warehouse and construction of indicators from this i2b2 data warehouseValues of indicators
4Cross-sectional study to assess the ability of indicators to detect inappropriate prescriptions of oral anticoagulantsSamples of patient hospital stays (type 1 samples as described in step 3) for primary and secondary analyses; three additional samples of patient hospital stays (defined as samples of types 2, 3 and 4; see the 'Methods and analysis' section for definitions) for secondary robustness analysesPrimary statistical parameter for each indicator: prevalence of inappropriate prescriptions of oral anticoagulants estimated from the data warehouse in comparison to the reference (information manually extracted by clinical research technicians in the patient hospital stay); secondary statistical parameters for each indicator: accuracy, reliability and robustnessValidation of indicators taking into account their ability to detect inappropriate prescriptions in relation to criteria of validation that will have been defined a priori
Cross-sectional study to assess performance of medical data search techniques for tracking or retrieving information needed for the construction of indicatorsSamples of patient hospital stays (type 1 samples as described in step 3) for the analysis of performance of tools tracking information for the construction of indicator; supplementary sample of patient hospital stays (defined as type 5 sample; see the ‘Methods and analysis’ section for definition) for assessing the ability of the data warehouse to identify targeted clinical situations or oral anticoagulant prescriptions covered by indicatorsPrimary analysis for assessing the performance of tools tracking information for the construction of indicators: recall, precision and F-measure; secondary analysis for assessing the performance of tools tracking information for the construction of indicators: qualitative analysis; secondary analysis for assessing ability of the data warehouse to identify targeted clinical situations or oral anticoagulant prescriptions: qualitative analysisProvision with useful information on performance of medical data search techniques using or not a data warehouse or Natural Language Processing tools
Cross-sectional study to assess the ability of other healthcare institutions to implement the same indicators with another data warehouse than i2b2Sample of hospital stays of patients cared at Rennes University Hospital in 2015 for targeted clinical situations or having had a prescription of oral anticoagulants, whose data will have been included in the eHOP data warehouseExtraction of data required for the construction of indicators from another data warehouse than i2b2: from the eHOP data warehouse at the Rennes University Hospital; primary statistical parameter: proportion of indicators that will be successfully automated from the eHOP data warehouseValidation of the ability of tools to be transferred to other institutions in relation to an expected proportion of indicators sucessfully automated that will have been defined a priori