Take the $2.8 trillion spent last year in the U.S. on health care and add another 70% to the total. The resulting amount, nearly $4.8 trillion, is what the federal government says we will spend by 2021. 

However, there are some technologies available now or in the near future that could reduce those expenditures. Here are three disruptive health care technologies that show promise in slashing health-care costs over time.

1. Genetic diagnostic testing
Overdiagnosis gets little attention, but it could add significantly to the nation's health-care costs. The term refers to scenarios where patients are diagnosed and treated for a disease that won't result in serious health issues.

For example, more than 240,000 men in the U.S. are diagnosed with prostate cancer annually. Half of these patients are classified as low risk, with only a 3% likelihood of the cancer progressing. However, 90% of low-risk patients receive treatments such as radical prostatectomy or radiation. These procedures increase costs and can result in further complications including incontinence and impotence.

Genetic diagnostic testing has the potential to help prevent much of this unnecessary spending. Genomic Health (GHDX) is one of a handful of companies already developing these types of tests. The company markets genetic tests for breast, colon, and prostate cancer.  It also has other products in development to screen for lung cancer, melanoma, and renal cancer.

As one example of possible savings, consider Genomic Health's prostate cancer test -- which sells for slightly more tha $3,800. That's much less expensive than the tens of thousands of dollars for the treatment procedures for the disease. 

2. Point of care decision support
Almost 14 years ago, the Institute of Medicine estimated that medical errors in the U.S. could cost $29 billion annually and result in as many as 98,000 deaths each year. Since then, additional studies have come up with varying numbers, but all agree on the enormous cost in lives and dollars resulting from medical errors.

Clinical decision support -- technology that helps physicians and other clinical professionals make better decisions -- has often been mentioned as a possible solution for reducing medical errors. However, despite increased availability of clinical decision support systems, a 2012 study conducted by Duke University found that use of these systems isn't widespread.

One reason behind the lack of high adoption rates could be that physicians haven't historically been able to access systems at the point of care -- where decisions are often made. However, that should change.

A survey last year by Vitera Healthcare found that 60% of health-care professionals own Apple (AAPL -1.10%) iPhones, with 45% using iPads. Around nine in 10 physicians expressed interest in using their mobile devices for reviewing and updating patient charts and ordering prescriptions -- ideal applications for clinical decision support. Apple has fostered a large ecosystem that now includes thousands of health-care applications, some of which already incorporate aspects of clinical decision support. In many ways, the company has revolutionized health care with its mobile devices.

Another potential factor that could partially explain lower adoption of clinical decision support is the quality of the support that the technology has provided in the past. IBM (IBM 0.62%) is one company intent on disruption for that front.  

Big Blue is now applying its Watson technology that became champion on the television game show Jeopardy! to the world of health care. Watson will use its natural language capabilities, hypothesis generation, and evidence-based learning to sift through patients' medical information and enormous volumes of clinical information available from clinical studies and journal articles to help physicians more accurately diagnose and recommend treatments.

3. Telemedicine
Where are the most expensive places to obtain health care? Hospitals and post-acute care facilities. Telemedicine offers the opportunity for patients to receive some types of clinical care at home, thereby lowering costs. Deloitte estimates that as much as $400 billion annually could be saved through effective application of in-home technologies.

Telemedicine has been around in various forms for decades, but the technology finally appears to be poised to take off. Nineteen states have passed laws requiring insurers to cover health services provided through remote technology. Efforts are also underway to advance federal legislation.

The niche has attracted interest from several big players, which is a good thing. For example, mobile communications giant Qualcomm (QCOM 2.19%) developed a platform for connecting medical devices at patients' homes to the cloud for external applications to use the data. This makes it easier for new applications to be developed that advance telemedicine functionality.

Research firm InMedica thinks that telemedicine could expand nearly 500% by 2017. If both Deloitte and InMedica are correct in their predictions, significant health-care savings should be possible.

Disruptions needed
Maybe the day will soon come when you can take a genetic test in your own house with the results sent electronically to your doctor, who then pulls up her iPad to confer with Watson about the best treatment -- to be provided to you remotely at home, of course. With more Americans aging and likely requiring more health care, disruptions like these are definitely needed.