When Proto reported on the problem of drug shortages in summer 2011 (“Museum Pieces”), the situation looked dire: From 2005 to 2011, the number of drugs that were in short supply or completely unavailable tripled. To some, the situation is improving.

Last year, for example, the University of Utah Drug Information Service (DIS) recorded 204 new drug shortages, down from 267 in 2011. DIS director Erin Fox attributes the decrease to the Food and Drug Administration’s newly expanded powers to prevent shortages, mandated by the Food and Drug Administration Safety and Innovation Act (FDASIA) passed last July. FDASIA requires all pharmaceutical manufacturers to notify the FDA if they plan to stop producing a drug, such as a chemotherapy agent, that treats a serious condition. Their warnings have helped the FDA take steps to head off shortfalls—for example, by finding other manufacturers to pick up the slack.

Yet many drugs—especially generic sterile injectable medications, such as certain older chemotherapy drugs and anesthetics—remain in short supply, which often forces physicians to use less-than-ideal alternatives. And the most critical shortage for hospitals right now, according to Fox, is of several essential drugs used to manage electrolyte abnormalities in patients receiving chemotherapy or in ICUs.

A major reason these shortages persist is that buyers for hospitals and clinics cannot observe manufacturing quality and have thus far assumed that product will be reliably delivered, says FDA economist Marta Wosinska. That gives manufacturers little incentive to differentiate themselves on manufacturing quality by upgrading factories and investing in other quality improvements. That’s a “recipe for trouble,” says Wosinska, “because there is very little margin for error.” Contamination and other quality-related problems that shut down production lines have caused most recent shortages, says Wosinska, who coauthored a paper on the problem in Clinical Pharmacology and Therapeutics with Janet Woodcock, director of the FDA Center for Drug Evaluation and Research, in February.

Drug shortages continue for other reasons too. Massachusetts General Hospital oncologist Bruce Chabner notes that worldwide demand for drugs is rising, leading to “leakage” of inventory to overseas markets. He also points to Medicare’s fixed reimbursement rates for certain generic injectables, which sets an artificially low price ceiling, making these products less profitable and therefore less attractive to produce.

Systemic changes may help reduce shortages. Stanford University oncologist Michael Link suggests that the government may need to take action to assure the availability of certain essential drugs, “since the market is not going to make sure that happens.” Chabner agrees that it’s important to help generic drug makers become more profitable. But he also argues for tougher regulations that would punish companies that create drug shortages by failing to deliver. “The generic market is almost like a public utility,” says Chabner. “They manufacture something that’s essential and life-saving for the public.”