There is no silver bullet for reforming America’s health care system, but medical experts have long agreed that digital patient records and electronic prescribing can help improve care and curb costs.

It seems straightforward. Just combine technology skills with investment money, and then develop innovative products. But to date, the push for a digital revolution in doctors’ offices has brought mostly frustration for the many companies big and small that are trying to conquer the field.

Just ask the Doerr brothers  John Doerr, the well-known venture capitalist who was an early backer of Google and Amazon, and Dr. Tom Doerr, a physician and software designer.

Dr. Doerr founded a software company in 1999, beginning with an electronic prescribing product and later adding electronic health records. His brother is the largest investor. After more than a decade, the venture has fewer than 500 doctors using its software.