Should I be worried by consent for disclosure?
7A signature on a piece of paper does not constitute valid consent in law. You should therefore ask to see the patient personally to ascertain that his consent was given entirely voluntarily, on the basis of full information as to how it would be used, that he was able to understand that information, and that he was competent to give such an opinion.
Is the patient normally unable to read, or was this the result of intoxication or confusion? If so he was almost certainly not legally competent at that time. In any case the patient is entitled to withdraw consent at any time and you must check that he still wishes to consent to the disclosure.
In view of the likelihood of this information being used as evidence you should make a record of the details of your consent procedures in the medical notes. If you believe it to be overwhelmingly in the public interest, or if it is a matter of life and death for him or for someone else, such consent may be unnecessary if it is impracticable to obtain consent.
In order to assist in the prosecution of a serious crime you may be permitted to disclose data without valid prior consent, but the GMC would consider only very serious crimes against the person justified such a disclosure.
You must obtain the data, without consent if necessary, if the police obtain a court order requiring you to do so. If you feel justified in disclosing the requested confidential medical data without valid consent you are obliged to limit the data to the minimum necessary to serve the purpose.
If you feel able to give an expert opinion you may do so, with the patient's permission, but most GPs prefer to confine their evidence to matters of fact recorded in the notes.
This is the safest policy and you should inform the police if you do not feel able to give such evidence. The safest method of providing data to a third party, especially if there is doubt about the validity of the consent and the patient's best interests, is to provide the patient with a copy of the relevant parts of the medical record under the terms of the Data Protection Act and ask him to give it to the police.