Its not diagnosis over the phone, its monitoring of certain diagnosed conditions. Informally patients with some chronic conditions already know what signs to look for to contact the GP or specialist nurse, and practices "believe" the patient and act accordingly without visits. I am thinking particularly of people with asthma or copd, just as this study is. With the telemonitoring equipment, this can be refined and improved on.
Even the Mail is finding it hard to find a downside.........