Over the last weeks, we have learned that major companies that make products we trust, like Volkswagen's diesel engines and Takata's air bags, have devised ways to rig test results so they look cleaner and safer than they really are. Yet far more widespread manipulation of test results is being done by pharmaceutical companies to get drugs approved by the U.S. Food and Drug Administration that turn out not to be as safe as promised.

In the pharmaceutical industry, virtually every company has been rigging tests for years to make the drugs we take look safer than they really are. Some of the techniques for rigging clinical trials are described in a recent assessment published by BMJ (formerly known as the British Medical Journal). They include drawing random samples for clinical trials from a population that exclude older people, women, and people with multiple health problems who may be more likely to have adverse reactions. The resulting "safety" of the drugs misleads physicians and their patients.

Other techniques include using high doses in shorter trials in order to produce positive results before adverse reactions become evident. Only later do patients learn about them the hard way. FDA regulations also allow companies to run multiple trials (at great expense, used to justify high prices) and handpick the most positive ones while obscuring evidence of toxic reactions.

Worse, unlike regulators for cars, planes, electronic devices, and appliances, who work to detect and stop rigged testing, the FDA division that reviews new drugs has long known about the ways that companies bias trials. This puts patients at serious risk. Based on reviews of hospital clinical charts, independent experts estimate approximately 128,000 patients die each year from adverse responses to properly prescribed drugs. And 2.7 million are hospitalized due to drug reactions. Those estimates do not even include problems related to over-prescribing, errors, and self-prescribing.

Exactly which drugs approved by the FDA's fast-track process have proved most dangerous to consumers? Given the central importance of drugs in modern medicine, you would think there would be a comprehensive tracking system at the FDA to provide this information by drug. But there isn't.

In fact, perhaps the most famous such failure is Vioxx, which Merck finally withdrew - following years of obfuscation - after it was estimated to have killed about as many people as the U.S. military lost in the Vietnam War. Note, it was the manufacturer that pulled the drug, not the FDA.

But there are many examples. Worst Pills, Best Pills (www.worstpills.org) is a reputable, subscription-based project of the advocacy group Public Citizen that tracks safety information on nearly 2,000 drugs.

Why does the FDA permit biased company trials for safety and efficacy? Perhaps it has something to do with Congress' underfunding of the FDA since the antiregulation period under President Ronald Reagan and then having companies fund the division that evaluates their drugs.

These practices subject patients to a double conflict of interest. First, companies test their own drugs for the public regulator, rather than having them tested independently. Then, companies pay the FDA a huge fee - $2.3 million in 2015 - to review each drug. Highly trained and skilled staff work hard to do thorough reviews. But the reviews are on the companies' terms - their criteria, their trials, their data, their deadlines, their funded patient groups clamoring for approval, and their money.

Reviewers do turn back or turn down drug candidates. Yet 90 percent of the drugs the FDA approves are judged by independent reviewers to provide few or no clinical advantages for patients over existing drugs.

And because these new drugs are inadequately tested, the results are predictable. One in every five new drugs ends up causing enough serious harm to lead the FDA to add the most serious black box warning, or remove the drug from the market - after the harm has been done.

This risk increases to one in three when reviews are accelerated under a special (and legal) process, requiring even higher fees from drugmakers.

Do patients really want faster access to drugs that provide few or no new benefits and have substantial risks of serious harm? Do they want an FDA that largely serves the industry that funds it by approving many new minor variations to increase sales, without good testing for safety?

A few clinically superior drugs are developed each year. But accelerated reviews and low, loose FDA criteria encourage companies to develop more minor variations that will get through the approval process, rather than focus on major advances. To encourage more superior drugs, the FDA needs to require tests for real clinical advances compared to risks of harm.

We need a congressional investigation, with subpoena power, to investigate how the FDA allows manipulations of true randomized trials that understate risks of harm. We need to end a third conflict of interest that endangers patients: The same FDA group that approves drugs as "safe" is responsible for investigating evidence of harm. Only 10 percent of FDA staff are assigned to drug safety. We need an independent, well-funded watchdog for patient safety.

Most important, as a public agency charged with protecting people from unsafe drugs, the FDA needs to be funded entirely by taxpayers. Drugs are now the fourth leading cause of death in America, tied with stroke. The FDA needs to stop contributing to this problem and help reduce the number of patients exposed to risks of serious harm.

Donald Light is a widely published expert on drug policy and a professor of comparative health policy at Rowan University.