Is it feasible to carry out the relevant screening diagnostic, and timely intervention procedures in a population based fashion with existing resources or with resources that could be obtained during the planning period, given sufficient political will.

To answer this question, it is necessary to estimate the total resources and costs involved in screening ,diagnosis, and effective intervention. The estimate will be based in part on the direct and indirect costs of each screening procedure ,multiplied by the estimated number of persons to be screened . this includes the initial investment required to put in place the capacity to perform screening ,as well as the recurrent costs of performing each screening procedure . indirect costs are difficult to calculate ,but should include at least the costs of the required planning, public education, and staff training .

Costs also include the costs of definitive diagnosis, based on the estimated number of people who will have abnormal results on screening , and the direct and indirect costs of performing the relevant confirmatory tests, as well as expenses for transport, record keeping, and communication.

The estimate of the costs of treatment should be based on the number of persons who are expected to need treatment, and should include the costs of long-term follow-up activities; such costs may be considerable, a sin the case of the control of high blood pressure . for many health risks, such as asymptomatic high blood pressure, short-term intervention at the individual level is unlikely to be worth while unless it is accompanied by long-term follow –up ;it is inappropriate to implement blood pressure screening until such long-term follow-up for those in greatest need can be ensured.

Reaching the population at greatest risk will often depend on involving members of the populationas active promoters of the effort. the costs associated with outreach and community involvement are legitimate component s of a screening budget and should be taken into account in feasibility studies.

Special costs must be considered in special settings. For example, the costs of screening and ensuring follow-up for nomadic populations may greatly exceed those for sedentary populations .in one area of Nepal local feasibility studies led to the conclusion that the lack of X-ray centers, qualified technicians , and doctors able to interpret radiographs meant that tuberculosis case-finding by sputum microscopy, implemented by auxiliary health workers…[with]…adequate training and long-term support was the most suitable method for tuberculosis screening .

It must be possible to apply the method in a population-based fashion; it is not sufficient to offer the detection procedure and the relevant follow-up measures only to those already receiving care for other reasons. The service must aim eventually to reach the entire population at substantial risk; initially, services may be targeted to those at the very highest risk and later expanded , as resources permit, to those at lower  but still significant levels of risk. It is essential that services should be targeted according to the known distribution of risk in the entire population and not according to the convenience of health care providers of the demands of the more privileged sectors of society.  Privileged sectors of society. The targeting of screening services is discussed further in .

It may not be feasible to use screening at a particular time because of a lack of resources for the proper implementation of the entire strategy of screening , diagnosis , and timely intervention. However, consideration of all seven criteria may lead to the conclusion that it would be highly desirable to implement a given strategy using screening as soon as possible to address a pressing problem. In this case , measures to achieve the necessary preconditions within a specified time frame could be considered; the essential criteria for implementing screening could then be reviewed at a later date. Other approaches could be used in the meantime or might even be preferable in the future .