Title: Primary care management of lower urinary tract symptoms in men: Development and validation of a clinical decision support tool (The PriMUS Study)
Funder: Health and Care Research Wales (Welsh Government)

Abstract: DESIGN: Diagnostic accuracy study SETTING: Primary care and community. TARGET POPULATION: Men consulting their GP for LUTS. INCLUSION/EXCLUSION CRITERIA: LUTS from a defined list, with infection or prostate cancer judged unlikely. Able to undergo index and reference tests. Men having current or previously planned active treatment for Male LUTS excluded. HEALTH TECHNOLOGIES BEING ASSESSED: Diagnostic statistical decision aid combining variables from simple tests to give diagnosis and treatment recommendation. Reference standard is urodynamics whereby bladder pressure is monitored during bladder filling and voiding by a thin catheter passed into the bladder. MEASUREMENT OF COSTS AND OUTCOMES: Predictive value of index tests used individually or in combination for each of three diagnoses established by the reference test: detrusor overactivity during filling; bladder outlet obstruction during voiding; and detrusor underactivity during voiding, assessed by regression analysis. Diagnostic accuracy validated by measuring sensitivity and specificity for diagnoses established by the reference test reported to standard criteria. Rates of referral from the CPRD dataset will be compared to that from the study population with GPs guided by index and reference test results. Qualitative analysis of interview data to map out future adoption. SAMPLE SIZE: We require 350 men for the model development cohort and 325 for the validation cohort giving a total of 675 men inflated to 880 men to allow for those who do not complete the protocol. For development we specified an event per variable (EPV) rate of five, assumed the lowest prevalent diagnosis to be detrusor underactivity (16%) and 11 variables would be in the model. For this diagnosis a cohort of 350 men would provide 56 events fulfilling the conditions at an EPV of five. DIFFERENCE BETWEEN CURRENT AND PLANNED CARE PATHWAYS: The NICE pathway will be the standard. Study participants will undergo assessment recommended for primary care by NICE. In addition, urine flow rate and residual urine estimation; optional in the NICE pathway and not routine in primary care, will be included. All men in the study will undergo urodynamics as the reference test for diagnostic accuracy; this is a specialist test in the NICE pathway. All results will be given to the GP with the diagnosis and recommended management options to decide on further care. PROJECT TIMETABLE AND RECRUITMENT RATE: We plan a 36-month study with a 6-month set up and pilot phase, a 24-month recruitment window and 6 months for analysis, write up and prototype testing. To collect 675 datasets assuming 20-25% attrition, we will recruit 880 men at a rate of 37 per month. Assuming a 25% consent to participate rate and an incidence of 2 men/practice/month (CPRD 2014) we should include 75 GP practices inflated to 100 to allow for non-recruitment to identify sufficient men. These will be managed through 3 research network hubs. Previous primary care studies led by our trials unit suggest set-up of 100 GP practices over 12 months is feasible. EXPERTISE IN TEAM: We have necessary skills in functional urology including reference test reporting (CH/RP/MD/AB), clinical measurement (MD/AB), test evaluation methodology (JD/JA), statistics (JD/YT), a CTU experienced in conducting primary care studies (KH/ET-J), qualitative methodology (NJ-W, AE), experience in running multi-centre studies in secondary (RP/CH) and primary care (AE/HA/ET-J, primary care leads and input from the user perspective (JR/TS).

Lay abstract: More than 10% of older men experience the need to pass urine more frequently than usual and often find their sleep interrupted by having to go to the toilet during the night. Some will find that their urine flow rate has become slower, and some will experience loss of bladder control. Such problems are distressing for men, affect their work and social life, and are a common reason why men visit a general practitioner (GP) with over 60,000 attendances yearly across the UK. They firstly need reassurance that they are not suffering from cancer or any other sinister medical condition. GPs follow established procedures when considering signs of cancer or these more serious conditions, but they have no easily available assessment tools to identify other more common causes of lower urinary tract symptoms (LUTS), or to advise men about the best treatment options for symptom relief. Because of this, men have to be referred to hospital based urology specialists for tests and diagnosis. We aim to establish a practical and accurate decision aid for use by GPs to diagnose the cause of LUTS in men and to assist decisions in determining appropriate person centred treatment. Success of the study will benefit men with LUTS, general practice and the wider health system by: -Enabling the use of an innovative and proven GP decision making aid across the NHS -Reducing waiting times before men are assessed and diagnosed -Giving men early access to appropriate treatment plans personalised to them -Reducing the number of men needing referral to hospital based urology specialists -Early referral of those men with more complex problems to specialist urology services The study will demonstrate if a set of simple test results can be incorporated into a computer software programme for use by GPs to establish a diagnosis of the cause of LUTS in an individual and therefore guide selection of appropriate treatment options to relieve symptoms. With the help of general practices across the UK, we will recruit 880 men with LUTS into the study. The tests will include men keeping a diary for a few days to record the timing and amount of urine passed, measuring urine flow with a small portable machine, and by asking men to complete symptom questionnaires. To assess the performance and accuracy of the tests, all men in the study will also need to have a more complicated test done by a specially trained nurse. This special test is called urodynamics and involves the passing of a thin tube into the bladder through which the bladder is then filled with water. Bladder pressure measurements taken during the test show up problems that might be causing the symptoms. A thin rectal catheter is also needed to control for changes in abdominal pressure. By comparing results of the simple tests with results of urodynamics we will identify which simple tests give best agreement. The top performing simple tests will then be incorporated into development of the decision making aid. The decision aid will be presented to GPs in a format that allows them to enter test results and then get a read out of the diagnosis and recommended treatment. The study will also consider practicalities for both patients and clinical staff in doing the simple tests in the general practice setting, and the ease in which the decision making tool can be used.

Research activity codes: 4.2 EVALUATION OF MARKERS AND TECHNOLOGIES;7.3 MANAGEMENT AND DECISION MAKING
Health categories: RENAL AND UROGENITAL