Screening for Fragile X Syndrome (Murray et al.) - NIHR Journals ...
Screening for Fragile X Syndrome (Murray et al.) - NIHR Journals ...
Screening for Fragile X Syndrome (Murray et al.) - NIHR Journals ...
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Human and financi<strong>al</strong> costs of screening46offered antenat<strong>al</strong> screening will need tounderstand in advance the possible dilemmaover termination of pregnancy that might ariseif the mother is found to be an FM or PM carrier,and prenat<strong>al</strong> diagnosis demonstrates a fem<strong>al</strong>efo<strong>et</strong>us with an FM. To date there are no publishedstudies on the psychologic<strong>al</strong> aspects of prenat<strong>al</strong>diagnosis in fragile X syndrome.Gen<strong>et</strong>ic counsellingIn carrier fem<strong>al</strong>es with a norm<strong>al</strong> IQ, any emotion<strong>al</strong>and cognitive problems may affect their ability tounderstand some of the in<strong>for</strong>mation given duringgen<strong>et</strong>ic counselling sessions. This may be moreapparent in FM fem<strong>al</strong>es; in PM fem<strong>al</strong>es the problemsmay be very slight or even absent. Specificadvice has been published on how to undertakegen<strong>et</strong>ic counselling <strong>for</strong> fragile X syndrome(McConkie-Rosell <strong>et</strong> <strong>al</strong>, 1995b). Also, the NHSResearch & Development Programme on Motherand Child He<strong>al</strong>th has now commissioned thisresearch group to carry out an empiric<strong>al</strong> studyon counselling and patient variables in gen<strong>et</strong>icdiseases including fragile X syndrome. Thisstudy will examine, among other things, theways in which the cause of the condition isdiscussed by counsellor and patient, andthe ways in which the counsellor checks thatin<strong>for</strong>mation has been understood.Gen<strong>et</strong>ic counselling should encourage individu<strong>al</strong>sto discuss fragile X syndrome with other familymembers. Those at risk of having affected offspringcould then request testing. It is possibl<strong>et</strong>hat feelings of guilt and stigmatisation mayhinder the transmission of in<strong>for</strong>mation b<strong>et</strong>weenfamily members; however, the <strong>Fragile</strong> X Soci<strong>et</strong>yhave reported that none of their members haveexperienced stigmatisation (Nuffield Councilon Bio<strong>et</strong>hics, 1993).CostsMeasures of costThe cost-effectiveness of a screening programmeis usu<strong>al</strong>ly expressed as the average cost of d<strong>et</strong>ectingone affected individu<strong>al</strong>. This can be readilyestimated from the separate unit costs <strong>for</strong> eachcomponent of the screening process. For example,with antenat<strong>al</strong> screening there is in<strong>for</strong>mationgiving, DNA testing, gen<strong>et</strong>ic counselling andprenat<strong>al</strong> diagnosis (some would <strong>al</strong>so include thecost of therapeutic abortion). The average costis computed from the estimated d<strong>et</strong>ection andf<strong>al</strong>se-positive rates, prev<strong>al</strong>ence and uptake rates.Sensitivity an<strong>al</strong>ysis can then be used to vary oneor more of the component costs and d<strong>et</strong>erminewhat aspect of the programme is mostprice sensitive.A more complex approach is to carry out a cost–benefit an<strong>al</strong>ysis in which the benefits are <strong>al</strong>someasured and v<strong>al</strong>ued. In the example of antenat<strong>al</strong>screening, the avoidance of treatment costsincurred by an affected individu<strong>al</strong> may be seen asa large benefit. The welfare or utility experiencedby a person with the disorder and their family,in not having to care <strong>for</strong> the affected person,or that gained by an early diagnosis, even whenit is decided to continue the pregnancy, aremore difficult to quantify and are usu<strong>al</strong>ly ignored.Another possibility is to v<strong>al</strong>ue the benefit tothose being screened by per<strong>for</strong>ming a willingnessto-payan<strong>al</strong>ysis, that is, by asking people howmuch they would be prepared to pay <strong>for</strong>the service.Estimated financi<strong>al</strong> costs and benefitsThe costs of two of the reported cascade screeningprogrammes have been estimated. In New SouthW<strong>al</strong>es, it was estimated that screening costs were$14,200 (Austr<strong>al</strong>ian, at 1986 prices) to preventone affected birth through prenat<strong>al</strong> diagnosis(Turner <strong>et</strong> <strong>al</strong>, 1986). In Murcia, Spain, the estimatedcost was $12,740 (US, at 1992 prices) peraffected birth prevented (Gabarron <strong>et</strong> <strong>al</strong>, 1992).At that time cytogen<strong>et</strong>ic testing was used so that,even <strong>al</strong>lowing <strong>for</strong> inflation, a modern screeningprotocol (see page 31) would be more costeffective.Neither of the studies estimated ortook into account the savings that might resultfrom births averted by means other than prenat<strong>al</strong>diagnosis. If these were included, the averagecost of preventing an affected birth would be evenlower. The corresponding lif<strong>et</strong>ime costs of care<strong>for</strong> an affected individu<strong>al</strong> have been estimatedto be in the region of $1–2 million (Lauria <strong>et</strong> <strong>al</strong>,1992) and may be as high as $4 million (Nolin<strong>et</strong> <strong>al</strong>, 1991).There are no published costs <strong>for</strong> strategies otherthan cascade screening. Antenat<strong>al</strong> screening canbe simply costed using Figure 8 and the unit costsof testing given in chapter 8; the unit costs ofin<strong>for</strong>mation giving, gen<strong>et</strong>ic counselling and prenat<strong>al</strong>diagnostic procedures are taken fromCuckle and colleagues (1996). These are shownin Table 15. First, we make a baseline assumptionthat no-one refuses the offer of screening, orprenat<strong>al</strong> diagnosis and termination of pregnancy,as appropriate, and that everyone has two pregnancies.Then the average cost of preventing eachaffected birth is £93,000. Reduced uptake does not