1.1 The need for the guideline

Post-menopausal bleeding (PMB) represents one of the most common reasons for referral to gynaecological services, largely due to suspicion of an underlying endometrial malignancy. Endometrial cancer is present in approximately 10% of patients referred with PMB. Formerly, the principal means of hospital investigation was by dilatation and curettage (D&C), but newer methods of investigation such as outpatient endometrial biopsy, transvaginal ultrasonography and hysteroscopy have superseded D&C. However, there is professional uncertainty concerning the most accurate, acceptable and efficient diagnostic approach.

The general practitioner (GP), as the usual first point of contact for a woman with this complaint, faces the unenviable task of assessing whether referral is required according to the clinical picture (which is not always clear-cut) and the woman's preferences. Furthermore, the growing use of hormone replacement therapy (HRT) has increased clinical uncertainty as to what constitutes unscheduled bleeding requiring referral for investigation.

The use of tamoxifen in the treatment of breast cancer has increased. Tamoxifen is associated with a higher risk of endometrial cancer. The presentation of PMB therefore requires urgent consideration in this group of women.

1.2 Evidence and context

Despite numerous publications on the issue of PMB, there is a paucity of evidence on how best to address it. The literature often fails to differentiate the post-menopausal from the peri-menopausal or the patient with dysfunctional uterine bleeding. Investigative techniques in many reviews are applied to a variety of gynaecological problems. The number of cases is often small and these represent local interest, skills or referral patterns. Consequently, techniques that may well be useful and are certainly widely used have an inadequate evidence base to support their recommendation in guidelines.

Where good quality evidence has been identified, specific clinical recommendations have been made. Areas lacking good evidence or where recommendations have been extrapolated are highlighted throughout this guideline.

Whilst recognising the limitations of the current evidence base, the guideline development group is aware that the absence of evidence does not necessarily imply any lack of effectiveness or accuracy for a specific diagnostic approach.

The current availability and use of investigative approaches among gynaecological departments in Scotland have been assessed so that these guidelines can be placed into the relevant local context. It is necessary to take into account the resource implications of recommendations for NHS Scotland otherwise there is a danger of recommending practices for which there is no current infrastructure.

Although this guideline identifies the practices for which the most robust evidence exists, clinicians managing women presenting with PMB will have to assess their practice in the light of this evidence and their own facilities and experience.

1.3 Defining PMB

The menopause is defined by the World Health Organisation as the permanent cessation of menstruation resulting from the loss of ovarian follicular activity.² This definition of the menopause is unhelpful in determining when an episode of bleeding can be described as post-menopausal. From a symptomatic perspective, post-menopausal bleeding describes the occurrence of vaginal bleeding following a woman's last menstrual cycle. There is some debate regarding the minimum time period that must have passed after the end of menstruation before PMB can be considered to have taken place. For the purposes of this guideline, an episode of bleeding 12 months or more after the last period is accepted as post-menopausal bleeding.

Abnormal bleeding in women using HRT can be difficult to assess. Unscheduled bleeding is the term used for breakthrough bleeding occurring in women on cyclical HRT or any bleeding in women on tibolone (Livial) or continuous combined HRT, although it can take up to six months for amenorrhoea to develop in the latter treatments. Consequently, assessment depends upon the type of regimen.³

For sequential regimens, abnormal bleeding may:

• be heavy or prolonged at the end of or after the progestogen phase, or
• occur at any time (breakthrough bleeding).

Pragmatically, bleeding on continuous combined regimens should be considered abnormal (requiring endometrial assessment) if:

• it occurs after the first six months of treatment, or
• it occurs after amenorrhoea has been established.

A more clinically-orientated method of interpreting diagnostic test results was used in drawing up some of the recommendations for this guideline. This focuses on the interpretation of the test result for a patient with a specified risk level for the disease. Several key recommendations are based upon evidence concerning the use of transvaginal ultrasound (TVUS). Two sources of information were combined to develop recommendations about the selection and interpretation of this investigation:

• test performance (i.e. sensitivity and specificity), by cut-off value used to determine whether a TVUS result is normal or abnormal;
• the probability that disease is present when the patient presents for investigation (i.e. pre-test probability).

Therefore this guideline uses probabilities to inform recommendations on the selection and interpretation of TVUS. Further details of the methodology of this approach is available alongside the electronic version of this guideline on the SIGN website.

1.5 Statement of intent

This guideline is not intended to be construed or to serve as a standard of medical care. Standards of care are determined on the basis of all clinical data available for an individual case and are subject to change as scientific knowledge and technology advance and patterns of care evolve. These parameters of practice should be considered guidelines only. Adherence to them will not ensure a successful outcome in every case, nor should they be construed as including all proper methods of care or excluding other acceptable methods of care aimed at the same results. The ultimate judgement regarding a particular clinical procedure or treatment plan must be made in light of the clinical data presented by the patient and the diagnostic and treatment options available. However, it is advised that significant departures from the national guideline or any local guidelines derived from it should be fully documented in the patient's case notes at the time the relevant decision is taken.

1.6 Review and updating

This guideline was issued in 2002 and will be considered for review as new evidence becomes available. Any updates to the guideline will be noted on the SIGN website: http://www.sign.ac.uk