We present a neutrino oscillation analysis of two particular data sets from the Daya Bay and RENO reactor neutrino experiments aiming to study the increase in precision in the oscillation parameters sin 2 2θ13 and the effective mass splitting ∆m 2 ee gained by combining two relatively simple to reproduce analyses available in the literature. For Daya Bay the data from 217 days between December 2011 and July 2012 were used. For RENO we used the data from 500 live days between August 2011 and January 2012. We reproduce reasonably well the results of the individual analyses, both, rate-only and spectral, defining a suitable χ 2 statistic for each case. Finally, we performed a combined spectral analysis and extract tighter constraints on the parameters, with an improved precision between 30-40% with respect of the individual analyses considered.