The fallout from Telstra’s national network outage on Wednesday was widespread, stalling trains and electronic payments, and preventing emergency calls to Triple Zero connecting. The company conducted more than 600 welfare checks on people unable to contact the emergency hotline, with seven people needing assistance.Errors with emergency calls continued into Thursday morning. But by Thursday afternoon, Telstra’s Chief Financial Officer Michael Ackland said customers can “feel confident” calling Triple Zero.While emergency calls have understandably gained the most attention, there are myriad other ways Australians’ health and wellbeing rely on stable network coverage. When disrupted, these are harder to measure.Health is now connected and digitalIn the post-COVID era, health care in Australia comes in many forms.While many people still see clinicians in person, these visits are supplemented with remote monitoring of symptoms, telephone calls, videocalls, as well as apps and internet-based information sources for self-management. So when Australia’s largest telecom provider goes down, it isn’t just emergency services like 000 that we lose. Many people use their mobile data to access health information and to support their wellbeing. This could mean chatting to an AI bot about mental health, looking up information about a condition or checking symptoms to see what steps to take next. Medical devices are also increasingly reliant on an internet connection. Many are now wifi-enabled (such as pace-makers) or have SIM cards (for example, continuous positive air pressure machines for sleep apnoea) to allow ongoing data transfer so patients and clinicians can track symptoms.Some people with diabetes use smartphone apps that not only monitor their blood glucose levels but communicate with their insulin pumps.There could have been disruptions in these systems, too, but there’s no reliable way to count this. A double blowOutages that prevent phone contact or data transmission also have a two-fold effect for consumers. First they prevent people from receiving care. This could be a scheduled call or video appointment with a GP, or an unscheduled call to a helpline. The nature of the outage also meant many of those stranded without normal care couldn’t be contacted with advice about what to do in the meantime.Second, outages create a backlog of services that need to be rescheduled or accessed at a later time. Rescheduling consultations can delay care for individuals, and create pressure on already busy clinicians and services. This can mean the disruptions to health care continue well after the initial outage issue is resolved.So, how many people were affected?The true impact in health care is hard to estimate. Australian health-care services are delivered by a diverse range of public and private providers, from big public hospitals to small single-clinician services. This means there is no one source of data to track missed appointments or a surge in people seeking care. And if one of those affected people was a clinician, it’s possible all of their patients would have been impacted during the outage. By nature, the outage is characterised by a lack of communication. This means we may never know how many people simply didn’t make their phone calls, access appointment links, look up symptoms, or use their medical devices.For instance, we hear about the Triple Zero calls that don’t connect, and tend to focus on the worst-case scenarios. But we are less likely to hear about what happened next, and the flow-on for these people and the health system. For example, we may never know about the people who tried to call but then chose to attend an emergency department, urgent care centre, general practice or other health service in-person to receive more immediate attention when they couldn’t get through to 000. Hours-long disruptions to transport also would have prevented some people from getting to in-person health appointments or collecting regular medications. But how do we measure this?Planning for uncertaintyWhen disruptions are planned, telecommunication companies try to warn customers so they can make alternative arrangements. In the case of unplanned outage events, Telstra advises that consumers could use either a hardwired or satellite internet connection at home. This allows people to use wifi calling if their device has the capability, or use a Voice over IP (VoIP) application to make calls during an outage.Health-care providers should certainly have contingency plans in place ensuring they have access to these kinds of hardwired or satellite internet connections. But for individuals, these suggestions are not feasible for everyone, especially considering one in ten of us rely solely on our mobile device for connectivity. Further, these contingency options rely on consumers having a certain level of digital literacy – to know when and how to use alternate methods when required.And digital literacy is not something you want to be acquiring in an emergency situation.We need better education for consumers and clinicians about what to do when coverage falls through. The Australian health-care landscape is a patchwork of in-person and digital services, so being prepared for technology failures is essential.If anything positive comes out of this, it may be greater awareness that planning for uncertainty is a health issue that we should all take seriously.Centaine Snoswell receives funding from the Medical Research Future Fund and Metro South Health for unrelated projects.