Entrevista a los capacitadores

The aim o f this Chapter was to review the existing literature on the costs and effects (or benefits) o f treating individuals with severe haemophilia on-demand or with prophylaxis. The results show that there has never been a definitive randomised controlled trial o f treatment on-demand compared to prophylaxis that has assessed the comparative costs and / or consequences o f both treatments. Moreover, very few uncontrolled data have been reported either on the long-term costs or health consequences o f treating individuals with severe haemophilia on-demand. Additionally, the majority o f evidence on the ability o f primary and secondary prophylaxis to reduce bleeding frequency and its associated sequeale (haemophilic arthritis) is from studies that were small in sample size, uncontrolled and o f inadequate duration to capture all outcomes o f interest. However, the results from these studies combined with long-term observational data from the Malmo Centre strongly suggest that prophylaxis can modify the frequency o f bleeding episodes and consequently the progression o f haemophilic arthritis if sufficient amounts o f clotting factor are administered at appropriate intervals.

Table 2.5: Studies reporting absenteeism from work or school by method o f replacement therapy

Study Mean annual days absent from work / study

Sample size Age at time of study

Notes

Prophylaxis On-demand

Aledort, 1994““^ Study doesn’t refer to prophylaxis p e r

se just annual amounts o f clotting

factor. Individuals receiving 0-500 iu/kg/year and >2,000 iu/kg/year were absent from work for a mean o f 8 and 3 days respectively. Precise group sizes are unclear.

Leisner, 1996^' 1 day per term at most

n=27

median 8.5 (range 2.9-17.7)

Mix o f primary and secondary prophylaxis. Children o f school age followed for a mean o f 30 months (range 7-76).

Lofqvist, 1997'*^ 0

n=15 7-15 years

Primary prophylaxis started between 1.0-2.0 years o f age. Patients have received clotting factor infusions o f between 4.7-8.9 ‘000s iu/kg/year. The study possibly duplicates some o f the data published in Nilsson, 1992.

Nilsson, 1992"^ 0.9 (range G.6-7.0)

n=20 between 13-17 years

Prophylaxis started at a mean o f 2.6 (range 1-4.5) years o f age. Patients with haemophilia A have received mean clotting factor infusions o f 1.5 (range 0.8-6.6) ‘000s iu/kg/year. 5.8 (range 1.0-20.0)

n=20 between 24-32 years

Secondary prophylaxis started at mean o f 7 (range 3-13) years o f age.

Patients with haemophilia A have received mean clotting factor infusions o f 0.4 (range 0.2-6) ‘000s iu/kg/year. Smith, 1996'^^ 0.9 n=16 all <18 years 1.3 n=42 all <18 years

Secondary prophylaxis. Mean follow- up period o f 26 months (range 6.5-72). Group differences were non­

significant. Severe haemophilia defined as <2 iu/dl.

Szucs, 1996*^^ 2

n = l l

10.6 n=39

Secondary prophylaxis. N o P-values quoted for differences between groups. Figures annualised. N ot all

individuals had severe haemophilia.

Szucs, 1998'^^ 8 n=399 mean 35.3 (sd. 14.6) 7.2 n=145 mean 35.3 (sd. 14.7)

Secondary prophylaxis. Includes days o ff work by a child’s carer. N o P- values quoted for differences between groups. Figures annualised. N ot all individuals had severe haemophilia.

Triemstra, 1995*^^ School 10 / work 22

n=980 mean 32 years

No definition o f prophylaxis or treatment details provided. Cross- sectional postal study.

Two published studies were found that examined the impact o f treatments on health- related quality-of-life (HR-QoL) in individuals with haemophilia. However, neither study adequately adjusted their results for potentially confounding factors such as clinical severity, age, HIV serostatus and previous clinical experiences. Thus, the results from these studies are o f limited use. Also in terms o f morbidity, only one (US ) study was found in which the potential comparative ability o f prophylaxis to reduce the need for hospital visits such as inpatient stays or orthopaedic procedures was reported.

A number o f studies were found that assessed the costs o f treatment: Szucs et al}^^

estimated the cost o f treating individuals on-demand and with (secondary) prophylaxis to be £11,400 and £17,700 per annum respectively and Smith et estimated these respective costs to be higher at £16,650 and £53,700 per annum. The literature search also produced three studies that claimed to be cost-effectiveness analyses o f prophylaxis. However, one o f these studies was found to be a cost analysis and not a cost-effectiveness a n a l y s i s O n e o f the remaining two evaluations was limited because few treatment details were provided, results were not adjusted for differences between patient groups, no details were provided as to how individuals were assigned to the two different treatment groups and no sensitivity analysis was performed on the incremental cost-effectiveness r a t i o T h e final study by Smith et al}^^ provided the most comprehensive information on cost-effectiveness to date. However, the data used in this study related to individuals who received secondary prophylaxis and no attempt was made to link final intermediate outcomes (joint bleeds) to final health outcomes (eg. the development o f haemophilic arthritis). Therefore, although it is relatively clear that prim ary prophylaxis can prevent bleeding and is more costly than on-demand treatment, it currently remains uncertain whether it is cost-effective.