These could be really big – improvements in complete river catchments like the Thames and new marine protected areas.
Participation among eligible patients was almost complete, and the catchment areas for cases and controls were comparable.
A modelling framework is presented which gives catchment-wide estimates of long-term stream water chemistry using complete spatial coverage of catchment characteristics combined with measurements of stream water chemistry at a limited number of sites.
In particular, for storm sizes much smaller than the dimension of the catchment, a complete resonance effect occurs for infinite combinations of the direction and speed of the moving rainstorm.
The study was large, population-based, with a well defined primary catchment area, complete registration, and long-term follow-up.
Blacketts, the final GP practice in Darlington PCT's catchment area, completed its upload of some 9,200 records from its Emis LV system this week.
"By the time the restoration of the catchment is completed, the moor will be able to hold the equivalent of more than 6,000 Olympic-sized swimming pools of water.
In all these cases, participation was much lower than in Factory A and Factory B, and the percentage of completed questionnaires from the catchment population ranged from 12.4% to 35.7% (Table 1).
Other potential biases of this study should be limited, given the almost complete response rate, the similar catchment area for cases and controls and the administration of a standard questionnaire under similar conditions.
In addition, the almost complete case ascertainment in the catchment areas, the nearly complete participation of identified cases and controls, and the use of a validated and reproducible questionnaire (Franceschi et al, 1993; Decarli et al, 1996) contributed to strengthen our findings.
