Context-Specific Economic Evaluation for Molecular Pathology Tests: An Application in Colorectal Cancer in the West of Scotland.

OBJECTIVES: The cost-effectiveness of molecular pathology testing is highly context dependent. The field is fast-moving, and national health technology assessment may not be relevant or timely for local decision makers. This study illustrates a method of context-specific economic evaluation that can be carried out in a limited timescale without extensive resources. METHODS: We established a multi-disciplinary group including an oncologist, pathologists and a health economist. We set out diagnostic and treatment pathways and costs using registry data, health technology assessments, guidelines, audit data, and estimates from the group. Sensitivity analysis varied input parameters across plausible ranges. The evaluation setting was the West of Scotland and UK NHS perspective was adopted. The evaluation was assessed against the AdHopHTA checklist for hospital-based health technology assessment. RESULTS: A context-specific economic evaluation could be carried out on a timely basis using limited resources. The evaluation met all relevant criteria in the AdHopHTA checklist. Health outcomes were expected to be at least equal to the current strategy. Annual cost savings of £637,000 were estimated resulting primarily from a reduction in the proportion of patients receiving intravenous infusional chemotherapy regimens. The result was not sensitive to any parameter. The data driving the main cost saving came from a small clinical audit. We recommended this finding was confirmed in a larger population. CONCLUSIONS: The method could be used to evaluate testing changes elsewhere. The results of the case study may be transferable to other jurisdictions where the organization of cancer services is fragmented.

The photochemistry of some main chain liquid crystalline 4,4'-stilbene dicarboxylate polyesters.

Several aspects of the photochemistry and photophysics of four main chain liquid crystalline polyesters with a rigid trans-stilbene 4,4'-dicarboxylate mesogen as chromophore and flexible spacer groups are reported. The three polymers with the longest 'spacer' groups are liquid crystalline at room temperature, two have smectic phases. Chromophore aggregation has a dramatic effect on the photophysics and photochemistry of these polymers. Each of the polymers in poor solvents or as films has greatly perturbed UV-Vis absorption and fluorescence spectra due to aggregation of the stilbene chromophore. These effects are more pronounced upon annealing above the glass transition temperature, T(g), and in the mesophase. Film fluorescence is excitation wavelength dependent and is suppressed at elevated temperatures. The stilbene 'environment' in both films and solution is clearly heterogeneous and energy transfer processes relatively slow. The dominant photochemical reaction upon direct excitation above 300 nm is 2 + 2 photocycloaddition rendering polymer films insoluble. No significant trans-to-cis photoisomerization can be detected upon initial irradiation of the polymer films. There is evidence for the formation of aldehyde and carboxylate functionality upon irradiation in the presence of air. Loss of the aggregate UV-Vis absorption and fluorescence occurs during irradiation. Difference UV-Vis spectra of irradiated films suggest preferential initial consumption of dimeric aggregates. Loss of stilbene UV-Vis absorption upon irradiation above 300 nm can be partly photoreversed upon subsequent 254 nm irradiation. The rate of stilbene chromophore loss from films increased significantly above Tg and in the smectic phase above room temperature.