Interventions:
The rationale for the selection of the comparators was clear. The two interventions were appropriate comparators.
Effectiveness/benefits:
The clinical analysis was based on a well-conducted RCT. The internal validity was ensured by the following features: the randomised design; the detailed reporting of the sample selection procedure (reasons for exclusion, refusal, withdrawal, or ineligibility); the use of power calculations and other statistical tests to consider potential baseline differences; the blind assessment of outcomes; and the use of the intention-to-treat principle. Also, the key clinical outcomes were assessed using appropriate tools, but the trial was performed in only one centre and the authors acknowledged that this was a limitation of their analysis. A cost-consequences analysis was conducted and no summary benefit measure was available, so the clinical outcomes were disease-specific.
Costs:
Only the drug costs were included. The economic perspective was not explicitly stated and typical sources were used for the drug costs. The price year was not explicitly reported, but the costs were derived from databases published in 2006. The resource quantities reflected the actual treatment patterns in the authors’ setting, but the unit costs and resource quantities were not presented separately. Statistical tests were carried out to assess the significance of cost differences.
Analysis and results:
A synthesis of the costs and benefits was not performed as a cost-consequences analysis was carried out. The issue of uncertainty was not explored, and no sensitivity analyses were carried out. The authors stated that a potential limitation of their analysis was the lack of distinction between different diagnostic groups. They also noted that the GNP follow-up might be transferable to other specialist areas with less complex, high-volume illnesses such as irritable bowel syndrome.
Concluding remarks:
This preliminary study was based on simple, but valid methodology. The economic analysis was limited to drug costs and further studies are needed to corroborate these preliminary findings.