Validation and reproducibility of computerised cell-viability analysis of tissue slices

BACKGROUND: The identification of live cells using membrane integrity dyes has become a frequently used technique, especially with articular cartilage and chondrocytes in situ where tissue slices are used to assess cell recovery as a function of location. The development of a reproducible computerised method of cell evaluation would eliminate many variables associated with manual counting and significantly reduce the amount of time required to evaluate experimental results. METHODS: To validate a custom computerised counting program, intra-person and inter-person cell counts of nine human evaluators (three groups – unskilled, novice, and experienced) were compared with repeated pixel counts of the custom program on 15 digitised images (in triplicate) of chondrocytes in situ stained with fluorescent dyes. RESULTS: Results indicated increased reproducibility with increased experience within evaluators [Intraclass Correlation Coefficient (ICC) range = 0.67 (unskilled) to 0.99 (experienced)] and between evaluators [ICC = 0.47 (unskilled), 0.85 (novice), 0.93 (experienced)]. The computer program had perfect reproducibility (ICC = 1.0). There was a significant relationship between the average of the experienced evaluators results and the custom program results (ICC = 0.77). CONCLUSIONS: This study demonstrated that increased experience in cell counting resulted in increased reproducibility both within and between human evaluators but confirmed that the computer program was the most reproducible. There was a good correlation between the intact cell recovery determined by the computer program and the experienced human evaluators. The results of this study showed that the computer counting program was a reproducible tool to evaluate intact cell recovery after use of membrane integrity dyes on chondrocytes in situ. This and the significant decrease in the time used to count the cells by the computer program advocate its use in future studies because it has significant advantages

Informing the process of consent for surgery: identification of key constructs and quality factors

Background Informed consent is a fundamental requirement of any invasive procedure. Failure to obtain appropriate and informed consent may result in unwanted or unnecessary procedures, as well as financial penalty in case of litigation. The aim of this study was to identify key constructs of the consent process which might be used to determine the performance of clinicians taking informed consent in surgery. Methods A multimodal methodology was used. A systematic review was conducted in accordance with PRISMA guidelines to identify evidence-based components of the consent process. Results were supplemented by semistructured interviews with senior trainees and attending surgeons which were transcribed and subjected to emergent theme analysis with repeated sampling until thematic saturation was reached. Results A total of 710 search results were returned, with 26 articles included in the final qualitative synthesis of the systematic review. Significant variation existed between articles in the description of the consent procedure. Sixteen semistructured interviews were conducted before saturation was reached. Key components of the consent process were identified with broad consensus for the most common elements. Trainers felt that experiential learning and targeted skills training courses should be used to improve practice in this area. Conclusions Key components for obtaining informed consent in surgery have been identified. These should be used to influence curricular design, possible assessment methods, and focus points to improve clinical practice and patient experience in future