  We present a framework to combine data from the latest neutrinoless
double-beta decay experiments for multiple isotopes and derive a limit on the
effective neutrino mass using the experimental energy distributions. The
combined limits on the effective mass range between 130-310 meV, where the
spread is due to different model calculations of nuclear matrix elements
(NMEs). The statistical consistency (p values) between this result and the
signal observation claimed by the Heidelberg-Moscow experiment is derived. The
limits on the effective mass are also evaluated in a (3+1) sterile neutrino
model, assuming all neutrinos are Majorana particles.
