What Sidaway decided
Sidaway v Board of Governors of the Bethlem Royal Hospital [1985] asked how much a doctor must tell a patient about the risks of treatment. The majority of the House of Lords applied a Bolam-style approach: the duty to warn was judged largely by what a responsible body of medical opinion considered appropriate to disclose. Crucially, Lord Scarman dissented, arguing for a patient-centred standard built around what a prudent patient would want to know. His dissent read, in hindsight, like a preview of Montgomery.
The facts
Mrs Sidaway underwent spinal surgery and was not warned of a small risk, around one to two per cent, of serious cord damage. The risk materialised. Under the law as it then stood, because responsible medical opinion supported not routinely disclosing a risk of that magnitude, her claim failed. The same facts today would be decided very differently.
Why it matters now
In 2015 the Supreme Court in Montgomery expressly departed from Sidaway on consent. The centre of gravity moved from the doctor to the patient. Sidaway is now mainly of historical interest, but it is useful history, because so many consent forms and habits still carry its assumptions: that disclosure is a matter of professional discretion, and that a signature closes the question.
What it means for your clinic
If your consent process is a standard risk sheet and a signature, it is a Sidaway-era process. It answers the question the law asked in 1985, not the one it asks now. Montgomery requires evidence of a tailored dialogue about the risks this patient would find material, and McCulloch adds the alternatives. A modern, defensible process looks nothing like the one Mrs Sidaway's surgeon was allowed to rely on.
Where this sits in the story
Consent and negligence law did not arrive fully formed. It climbed, case by case. You can watch the whole arc, and see what each judgment added to the burden your records carry, in the interactive timeline. The related cases are linked below.
Watch the standard rise: 1957 to today →
Related: Montgomery · Chester v Afshar · Bolam · McCulloch