The data analysis is in progress with the aim to determine the differential cross sections for the 1H(d,pp)n breakup reaction at four deuteron beam energies between 300 and 400 MeV. The data havebeen measured with the use of the WASA detector at COSY-Jülich. This work is focused on the beam energy of 380 MeV (190 MeV/nucleon). Set of proton-proton coincidences registered at the Forward Detector is analysed on a dense grid of kinematic variables. The one of the main steps of the analysis is efficiency study. Their impact on the final accuracy of the result is discussed.