Evaluation of a water, sanitation, and hygiene education intervention on diarrhoea in northern Pakistan.

Research Evaluation of a water, sanitation, and hygiene education intervention on diarrhoea in northern Pakistan D. Nanan,1 F. White,2 I. Azam,3 H. Afsar,4 & S. Hozhabri5 Objective Inadequate water and sanitation services adversely affect the health and socioeconomic development of communities. The Water and Sanitation Extension Programme (WASEP) project, undertaken in selected villages in northern Pakistan between 1997 and 2001, was designed to deliver an integrated package of activities to improve potable water supply at village and household levels, sanitation facilities and their use, and awareness and practices about hygiene behaviour. Methods A case–control study was conducted during July–September 2001 to evaluate whether, after selected confounders were controlled for, children aged <6 years with diarrhoea were more or less likely to reside in villages that participated in the project than in villages that did not participate. Descriptive and logistic regression analyses were performed. Findings Children not living in WASEP villages had a 33% higher adjusted odds ratio for having diarrhoea than children living in WASEP villages (adjusted odds ratio, 1.331; P<0.049). Boys had 25% lower odds of having diarrhoea than girls (adjusted odds ratio, 0.748; P<0.049). A 2.6% decrease was found in the odds of diarrhoea for every yearly increase in the mother’s age (adjusted odds ratio, 0.974; P<0.044) and a 1.4% decrease for every monthly increase in the child’s age (adjusted odds ratio, 0.986; P<0.001). Conclusions The findings in this study may help refine the approach to future water, sanitation, and hygiene initiatives in northern Pakistan. The integrated approach taken by WASEP, which incorporates engineering solutions with appropriate education to maximize facility usage and improve hygiene practices, is a useful example of how desired health benefits can be obtained from projects of this type. Keywords Potable water; Water supply; Sanitation; Hygiene/education; Diarrhea/epidemiology; Child, Preschool; Evaluation studies; Case-control studies; Pakistan (source: MeSH, NLM ). Mots cle´s Eau potable; Alimentation eau; Assainissement; Hygie`ne/enseignement; Diarrhe´e/e´pide´miologie; Enfant aˆge pre´-scolaire; Etude e´valuation; Etude cas-te´moins; Pakistan (source: MeSH, INSERM). Palabras clave Agua potable; Abastecimiento de agua; Saneamiento; Higiene/educacio´n; Diarrea/epidemiologı´a; Infante; Estudios de evaluacio´n; Estudios de casos y controles; Pakista´n (fuente: DeCS, BIREME ). Bulletin of the World Health Organization 2003;81:160-165. Voir page 164 le re´sume´ en franc¸ais. En la pa´gina 165 figura un resumen en espan˜ol. Introduction Improvement of public health is the strongest and most frequent argument put forward in support of water and sanitation projects (1). Inadequate water and sanitation services adversely affect the health and socioeconomic development of communities, and the two outcomes are related (2, 3). An integrated package of activities aimed at improving water supply and sanitation facilities, providing appropriate hygiene educa- tion, and building local capacity for the management of water and sanitation resources is more likely to show significant health benefits than a programme that concentrates on one area alone (2, 4–7). Expected health benefits rely on water and sanitation programmes containing a combination of components most appropriate to the local context. During 1997–2001, the German Technical Cooperation Agency (KFW) contracted and funded the Water and Sanitation Extension Programme (WASEP) of the Aga KhanDevelopment Network (AKDN) to undertake a project in selected villages in Northern Areas and Chitral in northern Pakistan. The aim was to improve potable water supply at village and household levels, sanitation facilities and their use, and awareness and practices about hygiene behaviour. The health and hygiene education topics addressed included traditional concepts about diseases; promotion of latrine use and the safe disposal of faeces; domestic, environ- mental, and personal hygiene; food preparation, handling, and storage; transmission routes and prevention of waterborne diseases; and operation and maintenance of water sources. The Northern Areas and Chitral is a mainly rural, mountainous region approximately 72 496 km2; the population of 900 000 people live in villages that typically comprise 50– 1 Lecturer, Department of Community Health Sciences, The Aga Khan University, PO Box Stadium Road 3500, Karachi 74800, Pakistan (email: debra.nanan@aku.edu). Correspondence should be addressed to this author. 2 Professor and Chair, Department of Community Health Sciences, The Aga Khan University, Karachi, Pakistan. 3 Senior Instructor, Department of Community Health Sciences, The Aga Khan University, Karachi, Pakistan. 4 Community Medicine Resident, Department of Community Health Sciences, The Aga Khan University, Karachi, Pakistan. 5 Research Fellow, Department of Community Health Sciences, The Aga Khan University, Karachi, Pakistan. Ref. No. 02-0106 160 Bulletin of the World Health Organization 2003, 81 (3) 200 households. Villages differ by location in topography and geography, as well as by language, ethnicity, and socio- economic development. The main health facilities are run by the government and the Aga Khan Health Services, Pakistan (AKHS,P) of AKDN. Initially, WASEP selected 109 villages (population 100 000) based on pre-set criteria. At the end of 2001, 99 villages (population 88 000) were enrolled in the project: 68 from Northern Areas and 31 from Chitral. Intervention components delivered by WASEP using appro- priate technologies in an integrated manner were water supply, water quality, drainage, sanitation, and school- and commu- nity-based hygiene education. The planning and implementation methodologies have been described elsewhere (8). Implementation schedules were flexible, so the programme could respond to the characteristics and dynamics within each village. The Department of Commu- nity Health Sciences, Aga Khan University (AKU-CHS), also of AKDN, helped WASEP in 1998 to develop a planning and monitoring approach for the project. In 2000, AKU-CHS was contracted by WASEP to determine whether, using diarrhoea as the health outcome, the project influenced the health status of villages served by the project. Other institutions conducted evaluations on different aspects of the project, such as hardware performance related to water supply and water quality (9). Methods Study objectives In the planning stage, WASEP specifically identified a reduction in incidence of diarrhoea as a project health outcome. TheAKU- CHS team focused the evaluation on children, as this age group suffers the greatest health burden from diarrhoea (10–12). In children, malnutrition, lack of safe water, poor sanitation, poor hygiene, early motherhood, breastfeeding practices, and inadequate health care are among known risk factors for diarrhoea (13, 14). A case–control design was adopted (15–17) to determine whether, after controlling for selected confoun- ders, children aged <6 years with diarrhoea were more or less likely to reside in villages that participated in the project than in villages that did not participate. This approach to the evaluation treated the combined ‘‘package’’ of interventions as the main exposure variable — because implementation schedules and sequencing for component interventions were flexible it was difficult to assess the contribution of each component independently. As the study was conducted at the four-year point of a five-year implementation plan, some components were incomplete for some project sites. If the components were considered as part of an integrated whole, however, an interim evaluation of the project in achieving its health outcome could be determined. Data collection was confined to the five districts of Northern Areas and excluded villages in Chitral because of time and budget constraints. Selection of cases and controls The evaluation team used health centres of the AKHS,P to identify potential study participants. Four AKHS,P health centres in Ghizer district and two in Gilgit district were selected as recruitment centres on the basis of the location of the target villages that had completedWASEP interventions, the proximity of AKHS,P health centres to completed target villages, the diarrhoea caseload of the health centres (AKHS,P reports, 2000 and first quarter 2001), and logistical considerations. Children were eligible for the study if they attended the recruitment centres during the study period, were aged 4– 71 months, had been resident in the same village for the previous two weeks, and were accompanied by a parent or guardian who was willing to participate in the study (written consent was obtained). Infants aged <4 months were excluded, as diarrhoea may be difficult to differentiate from normal stool. Cases were defined as a child with diarrhoea (three or more loose, watery stools in the last 24 hours) and were episode-based. Children with diarrhoea that lasted two weeks or more (chronic disease) were excluded. Controls were defined as a child with any complaint other than diarrhoea and without a skin condition or worm infestation (skin conditions and worm infestations were excluded from controls because they are associated with poor hygiene, sanitation, or water quality) (4, 6). Cases and controls were frequency matched on the basis of health centre of recruitment and time of diagnosis (controls were selected within 24 hours of a case). Data collection Data for cases and controls were obtained from the accompanying parent or guardian on residence, sociodemo- graphics, and hygiene behaviour with a pre-tested structured questionnaire delivered at the health centre by trained interviewers. Information was later provided by WASEP on whether a subject’s village was in the project or not, the date of completion of a WASEP intervention for the three major components (water, sanitation, and hygiene education), and whether other groups (public or private sector) had health- related activities similar to WASEP’s in a village. In addition, AKHS,P indicatedwhether it had a health facility in the village or not. Interviewers at the health centre were blinded to the exposure status of cases and controls, and staff from WASEP were blinded as to whether a village included in the study was associated with a case or a control. The study was conducted between July and September 2001 — the peak season for diarrhoea. A minimum sample size of 200 cases and 200 con- trols was calculated as needed based on two-sided testing with a 0.05, power 0.80, and a detectable odds ratio of 2.0. Data were entered into EpiInfo software, version 6.04. The response rate for the study was 100% (although two individuals willing to participate had to drop out because of language difficulties). Overall, 982 questionnaires were completed and returned by 508 cases and 474 controls. Of these, 27 cases and 20 controls were rejected because an old version of the questionnaire was used inadvertently during the initial phase of data collection. Another 27 cases and 57 controls were rejected on the basis of age (<4 months or >71 months), and a further 48 controls were rejected on the basis of exclusion criteria for controls. In total, 454 cases and 349 controls were used in analyses (ratio of case:control, 1.3:1). Data analyses were conducted with SPSS software, version 10 for Windows. Results Descriptive analysis As expected, on the basis of AKHS,P data on reported diarrhoea for 2000, most participants were from Ghizer district. Some control children had multiple diagnoses, and primary and secondary diagnoses were not differentiated during data consolidation. Diagnoses in control children in descending order of frequency were respiratory, gastrointestinal, other 161Bulletin of the World Health Organization 2003, 81 (3) Water, sanitation, and hygiene education for diarrhoea in northern Pakistan conditions, infectious disease, and nutritional. Respiratory conditions accounted for >50% of control complaints. The boy:girl ratio was higher for controls than for cases (1.7 vs 1.2) (Table 1). In total, 286 (63%) cases and 170 (49%) controls were aged <2 years. Mothers of case children were slightly younger than those of control children: 72 (16%) mothers of case children were aged <25 years compared with 37 (11%) of mothers of control children. Nearly three out of four mothers in both groups had no formal schooling. Travel time from home to the health centre generally was less for cases than for controls. For children aged <2 years, 97% (440) of children in both groups were exclusively or partially breastfed (data not shown). Housing conditions were used as a proxy of socioeconomic status: little variation was found between case and control households with respect to construction materials, number of rooms for sleeping, and number of persons living in the household over the last three months. Children in the study came from 111 villages and represented a broad cross-section of the project area selected: 90 villages in Ghizer district and 21 in Gilgit district. Forty- three (39%) villages had WASEP interventions. Cases were more likely to come from non-WASEP villages than controls (55% vs 47%) (Table 2). According to AKHS,P, all 111 villages received ongoing hygiene education from their field teams. In addition, 19 (17%) villages had an onsite AKHS,P health facility: 205 (45%) case children lived in a village with an AKHS,P health facility compared with 144 (41%) control children. Approximately one-third of cases and controls came from villages where other groups (public or private sector) were working on water, sanitation, or hygiene-related issues. Data collected by AKU-CHS on knowledge, attitude, and practices about health and hygiene showed virtually no differences between cases and controls (data not shown). Data on length of time since completion of each of the three major intervention components (water, sanitation, and hygiene education) inWASEPproject villages were not used in analyses because of the uncertainty over completion dates. Logistic regression analysis Simple logistic regression with diarrhoea status as the dependent variable was conducted and the crude odds ratios examined. The independent variables used were: village received WASEP intervention (main exposure), any group other than WASEP worked in village, AKHS,P health facility located in village, child’s sex, mother’s educational level, child’s age (months), mother’s age (years), and travelling time to reach the clinic (minutes). The last three were treated as continuous variables in regression analyses. Children were more likely to have diarrhoea if they lived in a non-WASEP village, the child was a girl, mother’s age decreased yearly, and child’s age decreased monthly. These results were statistically significant (P<0.05) (Table 3). Possible interaction effects were examined between WASEP and AKHS,P and between WASEP and other groups that delivered health-related interventions similar to WASEP’s in the study villages. These effects were not significant statistically (data not shown), and no interaction terms were included in the final model. Multiple logistic regression using backward stepwise elimination was conducted with diarrhoea status as the dependent variable. Variables where the crude odds ratio had a P-value <0.20 were included as independent variables: village received WASEP intervention, groups other than WASEP worked in village, child’s sex, child’s age, mother’s age, and time to reach the clinic. Variables were eliminated from the model if they did not meet the criterion of P<0.05. Results for the final model indicated that after age of child, sex of child and mother’s age were adjusted for, children who did not live in a WASEP village had 33% higher odds of having diarrhoea than children who lived in a WASEP village (adjusted odds ratio, 1.331; P<0.049) (Table 3). Similarly, after the other variables in the final model were adjusted for, boys had 25% lower odds of having diarrhoea than females (adjusted odds ratio, 0.748; P<0.049). Mother’s age and child’s age were inversely related to diarrhoeal disease status: a 2.6% decrease was seen in the odds of having diarrhoea for every yearly increase inmother’s age (adjusted odds ratio, 0.974; P<0.044) and a 1.4% decrease for every monthly increase in child’s age (adjusted odds ratio, 0.986; P<0.001). Discussion Throughout the investigation, AKU-CHS remained indepen- dent from other agencies including WASEP, so that it could maintain objectivity during the evaluation process. Useful background information and information on the intervention status of villages during data collection were supplied by WASEP during the study’s design phase. A rigorous culling of cases and controls took place during data processing on the basis of pre-assigned inclusion and exclusion criteria; this resulted in exclusion of more than 20% of the questionnaires that were administered. The study was able to reveal a Table 1. Characteristics of cases and controls Characteristic No. (%) Case (n = 454) Control (n = 349) Ghizer district health centre Gupis 118 (26) 107 (31) Jandrote 64 (14) 48 (14) Sandi 125 (28) 90 (26) Yasin 102 (23) 64 (18) Gilgit district health centre Gulmit 9 (2) 17 (5) Hoper 36 (8) 23 (7) Sex Male 252 (56) 218 (62) Female 202 (45) 131 (38) Age of child (months) 4–23 286 (63) 170 (49) 24–71 168 (37) 179 (51) Age of mother (years) <25 72 (16) 37 (11) 25–29 179 (39) 146 (42) 30–34 123 (27) 87 (25) 35–39 72 (16) 71 (20) 40–49 8 (2) 6 (2) Mother’s education No formal schooling 336 (74) 260 (75) Primary 47 (10) 29 (8) Higher than primary 71 (16) 60 (17) Travel time to clinic (minutes) <30 182 (41) 119 (34) 30–59 88 (19) 81 (23) 60–89 105 (23) 72 (21) 590 79 (17) 77 (22) 162 Bulletin of the World Health Organization 2003, 81 (3) Research favourable result for WASEP; however, children who resided in WASEP intervention villages had statistically significant lower odds of having diarrhoeal disease than children who resided in non-WASEP villages. Overall, after known confounders were controlled for, the WASEP intervention seemed to account for an estimated 25% reduction in the incidence of diarrhoea in children. In addition, younger children, girls, and children of younger mothers were associated with a higher likelihood of diarrhoea. These findings may help to refine the approach to future water, sanitation, and hygiene initiatives in northern Pakistan. A detectable odds ratio for the study was estimated as 2.0. WASEP reported a 50% reduction in the incidence of diarrhoea in project villages on the basis of a preliminary pre- intervention post-intervention comparison that used data from their monitoring programme. During the study period, the calculated minimum number of cases (200) was exceeded; this increased the sample size, which resulted in greater statistical power to detect a smaller intervention impact of 25% rather than the 50% reduction originally assumed. The 50% reduction in diarrhoea reported by WASEP may be due in part to an ecological effect caused by a decreasing background level of diarrhoea during the project. Such an ecological effect would not be accounted for in a pre-post analysis, in which only internal comparisons are made over time: a case–control design would more easily account for such trends (15, 18). Selection bias may have occurred, because study participants were those attending AKHS,P health centres andmay not have fully represented the regional population. However, AKHS,P serves the general population and is the second largest health care provider in Northern Areas after the Government of Pakistan. The use of four preset criteria (target village completed intervention, proximity of health centre to completed target village, diarrhoea caseload, and logistics) to select AKHS,P health centres as recruitment centres also would have limited selection bias. The process identified two out of five possible districts in Northern Areas for the study; differences may exist between districts that are not associated with the selection criteria and this may have influenced results. Misclassification bias with respect to exposure is unlikely: villages were categorized on exposure by WASEP technical staff who would have been familiar with all project villages. Misclassification bias of outcome may have occurred: the nature and extent is difficult to determine. The inclusion of a laboratory test (e.g. stool culture) in the case definition would have increased the study’s difficulty and may have affected participation. Recall bias may have affected study results, but as information used in analyses was mainly sociodemographic, the effect is expected to have been small. Response bias from participants giving socially acceptable answers to questions may have accounted for the small differences observed between cases and controls on the knowledge, attitude, and practices section of the questionnaire. The agreement in knowledge, attitude, and practices results may reflect the presence of organizations, other than WASEP, that delivered similar health-related interventions in the project area. Approximately one-third of cases and controls resided in villages where other groups were working on water, sanitation, and hygiene-related issues, and AKHS,P reported ongoing hygiene education by their field teams in all 111 villages in the study. These activities could also contribute to a decreasing background incidence of diarrhoea. As the number of knowledge, attitude, and practices questions was limited, some caution in interpretation of results is warranted, and a broader evaluation of knowledge, attitude, and practices may have produced notable differences between cases and control. Use of direct observation rather than questionnaires may have provided a more accurate determination of hygiene practices, but the former also has limitations (19). Although a partitioning of any observed effect of WASEP on diarrhoea to each of WASEP’s three major component interventions or combination of components was considered, difficulty in defining ‘‘date of completion’’ of an intervention hampered the analysis. In addition, secondary analyses would have suffered from numbers too small for valid subgroup analyses. The observed effect of a 25% reduction in diarrhoea therefore must be considered as the result of all components combined, assessed over the geographical area of the study. A shortage of funds resulted in a planned pilot evaluation study being cancelled, and constrained fieldwork to 10 weeks. If sufficient funds had been available for a pilot phase, it may have been possible to refine the study design to answer questions other than the primary study question. However, WASEP treated the intervention components as an integrated package during project design and delivery; this was consistent with their assumption that community involvement in all phases of implementation was essential for sustainability. The approach allowed for flexibility in implementation tomeet the varying needs and capacities of villages. The period July– September was chosen for data collection to maximize the number of diarrhoea cases seen at the health centres and thereby to achieve the calculated sample size. In addition, communication and transportation can be difficult in some parts of the region during the winter months. A seasonal influence on disease incidence is likely if only in terms of caseload, although the greatest public health impact of the intervention on diarrhoea would be during the summer period. The health impact and outcome indicators of a water and sanitation programme are not easy to define and are difficult to measure (1, 5, 20–22), especially if the effect of each component is to be determined separately. It is more feasible to regard such programmes as a ‘‘package’’ of services and actions that, taken together, can influence the health of a person and the health status of a community. The integrated Table 2. Intervention related status of villages for cases and controls Village status No. (%) Cases (n = 454) Controls (n = 349) Water and Sanitation Extension Programme Yes 206 (45) 185 (53) No 248 (55) 164 (47) Aga Khan Health Services, Pakistan health facility in village Yes 205 (45) 144 (41) No 249 (55) 205 (59) Other group working in village Yes 175 (39) 126 (36) No 279 (61) 223 (64) 163Bulletin of the World Health Organization 2003, 81 (3) Water, sanitation, and hygiene education for diarrhoea in northern Pakistan approach adopted byWASEP, which incorporates engineering solutions with appropriate education tomaximize facility usage and improve hygiene practices, is a useful example of how desired health benefits can be obtained from projects of this type. Although the evaluation wasmade at an interim point of a scheduled five-year implementation plan, some sites had not completed the programme, and unexpected funding difficul- ties were experienced, our findings indicate that WASEP positively influenced the health status of villages served by the project, by reducing the incidence of diarrhoeal disease. n Acknowledgements We thank the study field interviewers and other faculty and staff of AKU-CHS, especially Zafar Fatmi, MasoodKadir, and Nasiruddin Muhammadali; Inam Yar Baig and Ghulam Abbas fromAKHS,P for generously providing access to patients who attended their health centres; and Tameez Ahmad and Karim Alibhoy of WASEP for collegial support. Conflicts of interest: none declared. Re´sume´ Evaluation d’une intervention portant sur l’eau, l’assainissement et l’e´ducation en matie`re d’hygie`ne contre la diarrhe´e dans le nord du Pakistan Objectif L’insuffisance des services d’approvisionnement en eau et d’assainissement nuit a` la sante´ et au de´veloppement socio- e´conomique des communaute´s. Le projet WASEP (Water and Sanitation Extension Programme), mis en œuvre dans quelques villages du nord du Pakistan entre 1997 et 2001, visait a` offrir un ensemble cohe´rent d’activite´s destine´es a` ame´liorer l’approvision- nement des villages et des me´nages en eau potable, les installations d’assainissement et leur utilisation et les connaissan- ces et pratiques des communaute´s en matie`re de comportements lie´s a` l’hygie`ne. Me´thodes Une e´tude cas-te´moins a e´te´ re´alise´e de juillet a` septembre 2001 pour examiner si, apre`s exclusion de certains facteurs de confusion, les enfants de moins de 6 ans atteints de diarrhe´e avaient une plus grande probabilite´ de re´sider dans les villages couverts par le projet que dans des villages non couverts. Des analyses descriptives et des analyses par re´gression logistique ont e´te´ effectue´es. Re´sultats En ce qui concerne la diarrhe´e, les enfants ne re´sidant pas dans les villages couverts par le WASEP avaient un odds ratio ajuste´ supe´rieur de 33 % a` celui des enfants re´sidant dans les villages couverts par le projet (odds ratio ajuste´ : 1,331 ; p<0,049). La probabilite´ d’avoir la diarrhe´e e´tait plus faible de 25 % chez les garc¸ons que chez les filles (odds ratio ajuste´ : 0,748 ; p<0,049). Elle pre´sentait une relation inverse avec l’aˆge de la me`re et de l’enfant, diminuant de 2,6 % par anne´e d’aˆge de la me`re (odds ratio ajuste´ : 0,974 ; p<0,044) et de 1,4 % par mois d’aˆge de l’enfant (odds ratio ajuste´ : 0,986 ; p<0,001). Table 3. Odds ratios for diarrhoea in children attending Aga Khan Health Services, Pakistan health centres in Northern Areas, Pakistan Variable Odds ratioa P-value Crude Adjusted Included in multiple regression analysisb Water and Sanitation Extension Programme intervention Yes No 1 1.358 (1.027–1.797) 1 1.331 (1.002–1.769) <0.049 Other group in villagec Yes No 1 0.903 (0.675–1.209) NAd Age of child (months) 0.984 (0.975–0.993) 0.986 (0.977–0.994) <0.001 Sex of child Male Female 0.750 (0.564–0.997) 1 0.748 (0.560–0.998) 1 <0.049 Mother’s age (years) 0.970 (0.946–0.995) 0.974 (0.949–0.999) <0.044 Time to clinic (minutes)c 0.999 (0.997–1.001) NAd Not included in multiple regression analysisd Aga Khan Health Services, Pakistan health centre Yes No 1 0.853 (0.643–1.131) Mother’s education No formal schooling Primary >Primary 1.092 (0.747–1.597) 1.370 (0.770–2.438) 1 a Numbers in parentheses are 95% confidence intervals. b P<0.02 for crude odds ratio. c Removed from final model during backward elimination regression. d NA: not applicable. e P-value50.02 for crude odds ratio. 164 Bulletin of the World Health Organization 2003, 81 (3) Research Conclusion Les re´sultats de cette e´tude peuvent servir a` affiner l’approche des initiatives futures en matie`re d’eau, d’assainisse- ment et d’hygie`ne dans le nord du Pakistan. L’approche inte´gre´e adopte´e par le projet WASEP, qui allie des solutions techniques a` une e´ducation approprie´e en vue de maximiser l’utilisation des installations et d’ame´liorer les pratiques d’hygie`ne, constitue un exemple utile de la fac¸on dont les avantages recherche´s sur le plan de la sante´ peuvent eˆtre obtenus graˆce a` des projets de ce type. Resumen Evaluacio´n de una intervencio´n de educacio´n en materia de agua, saneamiento e higiene para combatir la diarrea en el norte del Pakista´n Objetivo Los servicios inadecuados de agua y saneamiento perjudican a la salud y el desarrollo socioecono´mico de las comunidades. El proyecto Programa de Extensio´n de Agua y Saneamiento (WASEP), emprendido en determinadas aldeas del norte del Pakista´n entre 1997 y 2001, se concibio´ para hacer llegar un paquete integrado de actividades encaminadas a mejorar el suministro de agua potable a las aldeas y hogares, las instalaciones de saneamiento y el uso de las mismas, y las pra´cticas higie´nicas y la sensibilizacio´n al respecto. Me´todos Durante los meses de julio a septiembre de 2001 se emprendio´ un estudio de casos y controles para evaluar si, despue´s de controlar el efecto de algunas variables de confusio´n, los nin˜os menores de 6 an˜os con diarrea tenı´an ma´s o menos probabilidades de residir en aldeas que participaban en el proyecto que en aldeas que no lo hacı´an. Se efectuaron ana´lisis descriptivos y de regresio´n logı´stica. Resultados Los nin˜os que no vivı´an en aldeas abarcadas por el proyecto tenı´an una razo´n de posibilidades ajustada de padecer diarrea superior en un 33% a la de los nin˜os que vivı´an en las aldeas abarcadas por e´l (razo´n de posibilidades ajustada, 1,331; P < 0,049). Los nin˜os tenı´an un 25% menos de probabilidades de padecer diarrea que las nin˜as (razo´n de posibilidades ajustada, 0,748; P < 0,049). Se observo´ una disminucio´n del 2,6% de las probabilidades de sufrir diarrea por cada an˜o adicional de la edad de la madre (razo´n de posibilidades ajustada, 0,974; P < 0,044) y una disminucio´n del 1,4% por cada mes adicional de la edad del nin˜o (razo´n de posibilidades ajustada, 0,986; P < 0,001). Conclusio´n Los resultados de este estudio pueden ayudar a enfocar mejor las futuras iniciativas en materia de agua, saneamiento e higiene en el norte del Pakista´n. El enfoque integrado adoptado por el WASEP, que complementa las soluciones te´cnicas con una educacio´n apropiada para maximizar el uso de las instalaciones y mejorar las pra´cticas de higiene, es un valioso ejemplo de las posibilidades de mejora de la salud que brindan los proyectos de ese tipo. References 1. Cairncross S, Carruthers I, Curtis D, Feachem R, Bradley D, Baldwin G. Evaluation for village water supply planning. The Hague: International Reference Centre for Community Water Supply and Sanitation and John Wiley & Sons; 1991.p.75. 2. Department for International Development (DFID). Guidance manual on water supply and sanitation programmes. London: WELL and London School of Hygiene and Tropical Medicine for DFID; 1998. 3. World Bank. World development report 2000/2001. Attacking poverty. Washington (DC): Oxford University Press; 2001. 4. Huttly SRA. The impact of inadequate sanitary conditions on health in developing countries. World Health Statistics Quarterly 1990;43:118-26. 5. Samanta BB, Van Wijk CA. Criteria for successful sanitation programmes in low income countries. Health Policy and Planning 1998;13:78-86. 6. Thompson J, Cairncross S. Drawers of water: assessing domestic water use in Africa. Bulletin of the World Health Organization 2002;80:61-2. 7. Forget G, Sanchez-Bain WA. Managing the ecosystem to improve human health: integrated approaches to safe drinking water. International Journal of Occupational and Environmental Health 1999;5:38-50. 8. Programmes in northern Pakisitan. 1997-2001. Water and Sanitation Extension Programme. Gilgit: Aga Khan Foundation; 1995. 9. Final report: technical assistance and assessment of sustainability. Gilgit: Water and Sanitation Extension Programme; 2001. 10. United Nations Children Fund. The state of the world’s children. New York (NY): Oxford University Press; 1992. 11. Khan KS. Setting health care priorities in Pakistan. Journal of the Pakistan Medical Association 1995;45:222-7. 12. Ahmed M, Billoo AG, Murtaza G. Risk factors for persistent diarrhoea in children below five years of age. Journal of the Pakistan Medical Association 1995;45:290-2. 13. VanDerslice J, Popkin B, Briscoe J. Drinking-water quality, sanitation, and breastfeeding: their interactive effects on infant health. Bulletin of the World Health Organization 1994;72:589-601. 14. Feachem RG. Interventions for the control of diarrhoeal diseases among young children: promotion of personal and domestic hygiene. Bulletin of the World Health Organization 1984;62:467-76. 15. Cousens SN, Mertens TE, Kirkwood BR, Smith PG, Feachem RGA. Case-control studies of common childhood diseases: the example of diarrhoea. London: Macmillan Education Ltd for the World Health Organization; 1995. 16. Young B, Briscoe J. A case-control study of the effect of environmental sanitation on diarrhoea morbidity in Malawi. Journal of Epidemiology and Community Health 1987;42:83-8. 17. Daniels DL, Cousens SN, Makoae LN, Feachem RG. A case-control study of the impact of improved sanitation on diarrhoea morbidity in Lesotho. Bulletin of the World Health Organization 1990;68:455-63. 18. Gordis l. Epidemiology. Philadelphia (PA): W. B. Saunders Company; 1996. 19. Boot MT, Cairncross S, eds. Actions speak. The study of hygiene behaviour in water and sanitation projects. The Hague: IRC International Water and Sanitation Centre and London School of Hygiene and Tropical Medicine; 1993. 20. Nanan D, White F. Water, sanitation, and hygiene evaluation issues. Bulletin of the World Health Organization 2002;80:75. 21. Curtis V, Kanki B, Cousens S, Diallo I, Kpozehouen A, Sangare´ M, et al. Evidence of behaviour change following a hygiene promotion programme in Burkina Faso. Bulletin of the World Health Organization 2001;79:518-27. 22. Kolsky PJ. Diarrhoeal disease: current concepts and future challenges. Water, sanitation and diarrhoea: the limits of understanding. Transactions of the Royal Society of Medicine and Hygiene 1993;87:343-6. 165Bulletin of the World Health Organization 2003, 81 (3) Water, sanitation, and hygiene education for diarrhoea in northern Pakistan