[Publications German-speaking countries in high impact journals: development and validation of a search filter].

Publications German-speaking countries in high impact journals: development and validation of a search filter Abstract.
Background: The number of publications in journals with a high impact factor is an indication of a discipline's participation in international discourse. A search filter allows reliable and reproducible searches for specific publications.
Aim: Development and validation of a geographic search filter for publications by nursing scientists affiliated to German-speaking countries in nursing journals with a high impact factor.
Methods: The search filter was objectively developed following several steps: (i) creation of a development and a validation set, each consisting of relevant and non-relevant publications, (ii) generation of the search filter by means of text analysis of the development set, (iii) internal validation based on the development set and (iv) external validation using the validation set. The validity was examined regarding several accuracy parameters, e. g. sensitivity, specificity, positive predictive value (PPV) and number needed to read (NNR).
Results: The search filter correctly identified 22 of 30 relevant and 16 of 21 non-relevant publications in the development set: sensitivity 80 % (95 % CI 66 - 94), specificity 76 % (95 % CI 58 - 94), PPV 83 % (95 % CI 69 - 97). External validation yielded similar or better results: sensitivity 81 % (95 % CI 67 - 96), specificity 88 % (95 % CI 71 - 100), PPV 88 % (95 % CI 75 - 100). The NNR was 1.2 and 1.1, respectively.
Conclusions: The search filter has the potential to identify the intended publications.