NCDDP had been preceded by other activities. The Ministry of Health introduced a national program for provision of ORT through its clinics in September 1977. In spite of possible small contributions, the general consensus is that prior to 1984, no marked changes occurred in either utilization of ORS or the outcome measure of mortality.<sup>5</sup> '<sup>6</sup> '<sup>7</sup> Two controlled field trials'° of oral rehydration therapy in rural villages of two governorates in Lower Egypt (Menoufia, Dalahlia) were conducted around 1980. The impact of each of these trials was evaluated. The two evaluations reported dramatically different findings. The Menoufia study concluded that the ORT intervention efforts did not reduce diarrheal mortality among children. The Dakahlia study indicated around 50 percent less diarrheal mortality and 40 percent less overall mortality among children aged one month to five years for certain configurations of program interventions. Tekce (1982)f suggested that the difference in results could have been due to different intervention strategies. The Dakahlia trial had better elements (for example, periodic home visits, health personnel education, more reliance on nurses with higher credibility among mothers) than the Menoufia trial. These elements may have achieved fuller cooperation as well as provided better support for the mothers in utilizing the new therapy. The importance of these two impact studies for the national evaluation attempted here is that they provide needed baseline information (prior to NCDDP) on the clinical epidemiology and management of diarrheal episodes. Another source of information is a diarrhea surveillance study" in children under 3 years of age conducted in 6 sentinel communities.

As early as 198512, opinions were being expressed on the positive demographic impact of NCDDP activities. However, some observers were questioning the validity of conclusions drawn about causality. A detailed review was performed of the available sets of data<sup>13</sup> , concluding that the causality statements required firmer substantiation. Major concerns of the study were the reliability of the available data and their inadequacy for supporting more positive statements of impact.

Making use of more up to date information, several recent studies5<sup>6</sup> have attributed a substantial portion of recent child mortality declines in Egypt to ORT activities. The basic rationale of, and pieces of evidence presented in, these studies are summadzed below. The studies start by presuming that the successful application of ORT would result in a significant reduction in child mortality. This presu.nption rested upon three considerations. First, at least half of the infant and child deaths in Egypt prior to the 1980s were diarrhea-associated. This figure is supported by the civil registration statistics summarized in Table 1. Second, prior to the project, there was poor case management of diarrheal episodes. Third, the theoretical efficacy of ORS was well established.

The studies provide ample evidence that basic project input goals such as production and accessibility of oral rehydration salts, training of physicians and annual public education campaigns via the media were satisfied. Concerning the actual outputs of the project, the studies refer to greater knowledge of ORT and of the dangers of diarrheal episodes. They also report that the required changes in the management of acute diarrhea had occurred. The evidence on 2