An apparatus for patient data availability analysis, comprising: - an input module; - a data and model analysis module; and - an optimization module; wherein, the input module is configured to enable a user to specify a plurality of models, wherein each model being used in clinical research and predicting a disease outcome, wherein each model provides output as a function of model variables, and the input module is configured to enable the user to define at least some model variables for the plurality of models, and the input module is configured to enable the user to specify source variables, wherein a model variable can be derived from one or more source variables, and the input module is configured to enable the user to specify at least one data source; wherein, the input module is configured to receive a plurality of data records from the at least one data source, wherein each data record comprises at least one attribute; wherein, the data and model analysis module is configured to determine a set of available data records for each model from the plurality of data records, the determination for a model comprising utilization of the model variables for that model, the associated source variables and the at least one attribute for the plurality of data records; wherein the data and model analysis module is configured to determine a number of clean data records of the available data records for each model, wherein each of the available data records comprises a plurality of values, and wherein the clean data records are determined as those data records of the available data records that are missing less than a threshold number of values; wherein, the data and model analysis module is configured to determine a plurality of availability measures for the corresponding plurality of models, wherein the determination comprises utilization of the determined set of available data records for each model, and wherein the availability measure for a model comprises the number of clean data records for that model; and wherein, the optimization module is configured to rank and select a sub-set of models of the plurality of models as top models of data availability, wherein the selection comprises utilization of the plurality of availability measures. - an input module; - a data and model analysis module; and - an optimization module; wherein, the input module is configured to enable a user to specify a plurality of models, wherein each model being used in clinical research and predicting a disease outcome, wherein each model provides output as a function of model variables, and the input module is configured to enable the user to define at least some model variables for the plurality of models, and the input module is configured to enable the user to specify source variables, wherein a model variable can be derived from one or more source variables, and the input module is configured to enable the user to specify at least one data source; wherein, the input module is configured to receive a plurality of data records from the at least one data source, wherein each data record comprises at least one attribute; wherein, the data and model analysis module is configured to determine a set of available data records for each model from the plurality of data records, the determination for a model comprising utilization of the model variables for that model, the associated source variables and the at least one attribute for the plurality of data records; wherein the data and model analysis module is configured to determine a number of clean data records of the available data records for each model, wherein each of the available data records comprises a plurality of values, and wherein the clean data records are determined as those data records of the available data records that are missing less than a threshold number of values; wherein, the data and model analysis module is configured to determine a plurality of availability measures for the corresponding plurality of models, wherein the determination comprises utilization of the determined set of available data records for each model, and wherein the availability measure for a model comprises the number of clean data records for that model; and wherein, the optimization module is configured to rank and select a sub-set of models of the plurality of models as top models of data availability, wherein the selection comprises utilization of the plurality of availability measures.