Donnie lost a friend affected by dementia, and would like to know what sort of device could have been used to locate him

What is the best way to track someone with dementia?

A former colleague developed dementia. He wandered off and was found three days later in a small wood a few miles away. Sadly, he died on his way to hospital. What sort of electronic device could have been used to locate him sooner? I’m 85 and a Guardianista since 11 December 1953 (National Service call-up). Donnie

Location tracking is a rapidly growing field, to the point where it looks as though almost everyone will be tracked within the next decade or so. Parents are tracking children and pets, and sometimes their own parents. Health services and care homes are tracking patients. Local authorities and other employers are tracking lone workers, for safety reasons. Distributors and delivery services are tracking vehicles and sometimes couriers. Military organisations are tracking soldiers. Millions of people are using fitness bands to track themselves, their heart rates, their sleep patterns and so on.

As a result, there are plenty of options, including one that fits inside a shoe. Many devices are bought for personal use, but medical and commercial applications are leading the way.

Tracking tech

Today, most people carry mobile phones, which provide several ways to track you – assuming the phone is switched on. This was driven by the need to locate people who made emergency calls in the US.

The basic system uses the phone’s roaming signal, which polls nearby phone masts to find the best signal. The phone’s position can then be calculated by multilateration.

Most smartphones now use hybrid location systems for increased accuracy. This combines the cell-tower data with information from GPS satellite systems and, increasingly, from wifi networks. A GPS system works better in open countryside, but people moving around in city malls are easier to track via wifi. (Malls and department stores may use wifi to track people doing their shopping.)

The simplest way to track someone is therefore to put a mobile sim (subscriber identification module) into a pendant, badge or wrist-worn device. Devices that don’t have their own sim can get location information from GPS satellites or by using Bluetooth to pair with a nearby smartphone. However, every device will need some sort of network connection to send data to whoever is doing the tracking, so you may as well build it in.

Patient care

It has been estimated that more than 850,000 people in the UK are affected by dementia, but less than half have been diagnosed. People who have been diagnosed with Alzheimer’s disease or another form of dementia should ask their local medical services, and their local authority, for advice. “Wandering” is a known problem, and the Alzheimer’s Society website says that “one study found that 40% of people with dementia get lost outside their home”.

Many UK local authorities havetelecare systems and community-based alarm services with staff who respond to alarms. They may be free if they are necessary for patient care, though they may charge a small fee to people who would just like to have a backup in case of need. Some use products from Welbeing, a UK telecare provider set up by two local authorities before becoming a private company.

The OwnFone Footprint GPS tracker is another option. The AT Dementia website lists several other suitable products, including the MySOS GPS and the St Bernard Location Service GPS trackers.

Suppliers are usually members of the BHTA (British Healthcare Trades Association) and the TSA (Telecare Services Association).

Possible products

Skyguard’s MySOS tracker and personal safety alarm is an oval device with a big button to press if you need help. This makes a voice call to the incident centre, which will take the appropriate action. However, if you send a MySOS an SMS message, it will reply with a link to a web map that shows where it is. That would enable a friend or family member to find you if you were lost. MySOS is also sold as a safety alarm to lone workers and other potentially vulnerable people. It costs £10 per month.

The St Bernard Ease tracker looks like a wristwatch and also works as a mobile phone. You can assign a different number to each of its four keys. AT Dementia’s blurb says: “Carers can be sent alerts for different risk conditions: panic button, unsafe areas, low battery or user speed. Alerts for fall detection are also an option. These alerts can be sent to carers by SMS, e-mail or, for telecare users, directly to their response centre.” Pricing is opaque.

The Buddi is a wristband, and looks much like a fitness device. It has an alert button to call for help, but it also counts steps, monitors sleep, and detects falls. You can also set up “safe zones” on a map and the Buddi will send an alert if the wearer wanders into an unsafe zone.

You can rent a Buddi for £10 per week, including 24-hour support for alerts, or buy one for £249 and pay £5 a week for the monitoring service. It sounds like a confidence booster for someone who isn’t in patient care, while providing some peace of mind to friends and family.

The Mindme Alarm is a pendant device that provides continuous live tracking via GPRS signals. It costs £85 and then £16.50 per month for the Response Centre, but there are no charges for calls or texts.

Products like this have to be – once set up – extremely easy to use. They also need to be small, portable, robust and water-resistant, and have long battery life. They usually need, and probably come with, the support of a call centre.

Personal trackers

Many similar products are sold without tracking services, but that means somebody else has to take responsibility for monitoring the tracker and responding to any alerts.

In many cases, this won’t be a problem. Parents can track their children without much effort, because they are usually where they are supposed to be. People can track their ageing parents, with permission, though this raises much bigger privacy issues. Best friends could, I suppose, track each other, and in some cases, several people can share the burden. However, there won’t always be an easy answer.

The pendant-style Stray Star GPS tracker and GPS Tracker Watch are examples. They are used by local authorities, care homes, employers and individuals, but they are sold unlocked and sim free with no subscription services or other contracts. (Free GiffGaff sims can be preinstalled, and include a £5 credit.) These devices have SOS buttons and remote listening features, and they respond to SMS messages with a map location you can see on your smartphone. You can also do live tracking via a map on a web portal, which means anyone with the log-on details would also have access.

Live GPS tracking with these devices requires a sim with a data allowance, because they use GPRS to upload small packets of data. You have to set a time – every minute, every 10 minutes, every hour or whatever. More frequent updates give you a more accurate track. That costs more, but the website claims that “a month of location uploads every few minutes will still only amount to a few megabytes”.

There are lots of similar products at Amazon and more specialised websites, including brightly coloured smartwatches for tracking children. The Bestie is a British example.

Unfortunately, I have not tried any of these devices, but I’m sure many readers will have used them with relatives and possibly colleagues. If so, please share your tips on the best products and services, and any dire warnings about the practical and ethical problems involved.

Have you got another question for Jack? Email it to Ask.Jack@theguardian.com

This article contains affiliate links, which means we may earn a small commission if a reader clicks through and makes a purchase. All our journalism is independent and is in no way influenced by any advertiser or commercial initiative. By clicking on an affiliate link, you accept that third-party cookies will be set. More information.