Interventional procedures programme manual

Consideration of benefits

The Committee considers the nature of benefits, their magnitude, the ways in which they can be assessed and their duration. All these criteria need to be considered in the context of the natural history of the condition being treated or investigated, and compared with outcomes after established treatment options. There also needs to be evidence of sufficient benefit to justify subjecting a patient to a procedure and its risks. Minor improvements in outcome measures that do not seem to translate into real clinical improvements will not support a decision that a procedure is efficacious.

Outcome measures

Evidence of improved survival, reduced morbidity or improved quality of life carries more weight in decision‑making than surrogate outcomes (such as those shown by imaging or biochemical markers). The Committee may identify outcome measures for the procedure that it considers to be particularly informative and suggest these for future research and audit.

The absence of comparative studies

IPAC often considers evidence from single‑arm studies such as case reports and case series. Occasionally, the Committee may decide that more information is needed from studies that compare an active treatment against a sham procedure or standard treatment. Then, guidance may recommend that comparative studies are done.

Consideration of efficacy of procedures that provide diagnostic or monitoring information

When NICE develops guidance on a diagnostic procedure it is important to ensure that the assessment encompasses the value to patients of the diagnostic information generated by the procedure. The programme does not have the remit or methods to evaluate subsequent treatment in the management pathway, which may be influenced by the results of a diagnostic test. However, to arrive at a reasonable view of the efficacy of the diagnostic test used in the procedure, the Committee takes into account whether it can reasonably be considered to change clinical decision‑making and subsequent management in a way that is likely to benefit patients.

The scientific literature for diagnostic tests consists largely of studies of analytical and clinical validity. Evidence on the impact of diagnostic technologies on final patient outcomes (clinical utility) is generally limited. To conduct an assessment for interventional procedures guidance, NICE seeks specialist advice on the clinical utility of the diagnostic procedure so it can provide information on whether the diagnostic procedure can plausibly inform clinical decision‑making and so benefit patients. The Committee considers analytical and clinical validity data on the diagnostic procedure only in the context of advice that it has plausible clinical utility.

Short-term efficacy

This is almost always important. A procedure that does not provide benefit in the short term is unlikely to be considered efficacious. For some procedures, evidence of short‑term efficacy may be the only requirement. For example, for a new procedure to treat an acute illness, the expectation of long‑term benefit is implicit once the condition has been treated and the patient has recovered.

Long-term efficacy

This can be a problem for procedures that have not been used long enough to allow for lengthy follow‑up studies, and can mean the evidence on long‑term efficacy is small in quantity or of poor quality. Examples of procedures that must have durable results to be considered efficacious are insertion of prosthetic joint components, procedures to relieve urinary or faecal incontinence, and procedures intended to cure cancers.

Seriousness and frequency of reported adverse events

When assessing safety, both the seriousness and frequency of adverse events are considered. A low risk of very damaging complications is generally considered to be a more significant safety issue than a high risk of minor complications. Most importantly, patients (or their parents or carers, when appropriate) should be informed and should understand the risks when offered the procedure. This always means telling them the known risks, and it may also mean telling them that there is uncertainty about the frequency of complications – in particular uncommon and serious ones. This consideration informs the Committee's recommendations on consent.

Quantity of evidence on safety outcomes

The number of reported cases considered adequate to make or support a decision relating to the safety of a procedure is influenced by:

For a procedure that is used to treat a rare but rapidly fatal condition, safety data based on only a few reported cases may be considered adequate. In contrast, if a procedure is for a common condition that is not a serious threat to health, and theoretical concerns have been raised about a possible uncommon but serious complication, very large numbers of well‑reported cases may be needed to adequately assess its safety.

Quality of evidence on safety outcomes

Decisions relating to safety are strongly influenced by the completeness with which adverse events appear to have been reported in the available studies and case series. Some studies make clear that safety outcomes have not been reported at all, whereas other studies present complications in great detail (to the extent that some of these outcomes may be judged as expected sequelae of the procedure). Particular difficulties arise in making decisions about safety when:

In making decisions relating to safety, the Committee generally adopts a proportionate risk‑averse approach, preferring to take account of higher complication rates and advice that raises concerns rather than low complication rates (when studies vary) and more optimistic advice. The Committee will also take into account the quality of the evidence base because variation in safety findings between studies may be related to study quality. A precautionary approach is especially important when considering procedures for long‑term conditions with good overall prognosis.

Impact of adverse events on patients' quality of life

The Committee takes account of the impact of complications on patients' quality of life, informed by advice from both patients and specialists. Lay members of the Committee in particular are able to make contributions on this matter.

Short-term safety

This is always important and includes complications (morbidity and mortality) during the procedure and shortly afterwards. Interventional specialties commonly use the first 30 days after the procedure as the interval for 'postoperative complications' in reported series.

Long-term safety concerns

Some procedures pose risks of adverse events that only become apparent in the longer term. The likelihood of these occurring may either be suggested by the nature of the procedure (for example, insertion of a prosthesis) or raised by specialist advisers on the basis of their experience. Lack of long‑term safety data is a frequent problem. If there is uncertainty or concern about long‑term safety in the context of the severity of the condition being treated, the Committee may decide that the safety data are altogether inadequate. If the risk of delayed adverse events is only theoretical or sufficiently remote, the decision may be simply to advise reporting of these if and when they occur, to inform future practice.