Reversing a long-term trend, prices for more than one in four generic medicines widely used by older Americans increased in 2013, some very sharply, according to a survey by AARP. Generic drug prices on average are still falling, but the increases for certain classes of drugs may be a sign of more to come, the advocacy group says, because industry consolidation is reducing competition, manufacturing quality problems are causing shortages and the number of blockbuster brand-name medicines going off patent has fallen since a huge surge a few years ago.