The family of the seven-times Formula One world champion Michael Schumacher has assured fans he is being well cared for as they prepare to celebrate his 50th birthday on Thursday.

Schumacher, who retired from racing in 2012, has not been seen in public since he suffered severe head injuries in a skiing accident five years ago. The German is being cared for at home in Switzerland.

“You can be sure that he is in the very best of hands and that we are doing everything humanly possible to help him,” the family said in a statement that made a rare comment about his condition.

“Please understand if we are following Michael’s wishes and keeping such a sensitive subject as health, as it has always been, in privacy,” it added.

The family said an official Michael Schumacher app will be released on Thursday to enable fans to review all his career successes. The Keep Fighting Foundation has also created a virtual museum.

“The app is another milestone in our effort to do justice to him and you, his fans, by celebrating his accomplishments,” the family said. “Michael can be proud of what he has achieved, and so are we ... we want to remember and celebrate his victories, his records and his jubilation.”

Ross Brawn, who helped mastermind Schumacher’s success at Benetton and Ferrari, and has visited the former champion in Switzerland, says the driver’s wife, Corinna, and family are right to be guarded over the information they release.

“I am constantly in touch with Corinna, and I totally agree with their decision,” Brawn told the Press Association. “Michael has always been a very private person and that’s been a guiding principle in his career, his life and his family always agreed with that choice.

“It’s completely understandable that Corinna has wanted to maintain the same approach, even after the tragic event, and it’s a decision we must all respect. I’m sure the millions of people who are still Michael fans will understand it, too.”

Schumacher won his first two titles with Benetton in 1994 and 1995 before five in a row with Ferrari between 2000-2004. He remains the sport’s most successful driver, with a record 91 grand prix wins. Britain’s Lewis Hamilton, now a five-times world champion with 73 wins, has already claimed several of the German’s records and could ultimately match his title tally if he continues his current rate of success.

“Lewis is certainly capable of matching and surpassing Michael’s other records,” added Brawn, now acting as the head of motorsport for F1. “There’s no doubt that Lewis and Michael are amazingly talented. In fact, it’s their natural talent that unites them. The way in which they achieved their wins is where they differ.

“Michael treated his driving career as though it was a mission to which he dedicated himself completely from the first to the last day. In some ways, Lewis has taken longer to find his way, and today it seems he has found that way more from outside the sport than from inside it.”