Children at Risk of Developing Dehydration from Diarrhoea: A Case-control Study

Transcription

1 Children at Risk of Developing Dehydration from Diarrhoea: A Case-control Study by Farid Uddin Ahmed a and Enamul Karim b a Comilla Medical College/Hospital, Bangladesh b Institute for Health Sector Development (IHSD), London, UK Summary To identify the factors related to dehydration from diarrhoea, a hospital-based case-control study was carried out among under-2-year-old Bangladeshi children. The study compared 80 cases who had some or severe dehydration with 160 age-matched controls who had no signs of dehydration. All the cases and controls were examined and the mothers were interviewed in the hospital and followed at home on the 14th day of illness. Thirty-eight factors were studied for their probable influence on the development of dehydration. In bivariate analysis, 17 factors were found to be associated significantly with the development of dehydration and were treated with stepwise logistic regression analysis. A combination of vomiting, oral rehydration therapy at home, mother s dirty finger nails, and residing more than 3 km away from the hospital provided the maximum sensitivity (77.5 per cent) and specificity (91.2 per cent) for predicting development of dehydration. These prognostic factors would be helpful for community health workers to identify children at risk of developing diarrhoea-associated dehydration, and preventive strategies could be designed to alter the prognostic factors. Introduction Diarrhoeal diseases have long been recognized as a leading cause of morbidity and mortality, with global diarrhoeal episodes of 1000 million and the death of 4 million children under 5 years old. 1,2 About 2 3 per cent of children with diarrhoea develop life-threatening dehydration which contributes to mortality. 3 A few early signs and symptoms, and socioeconomic, biological, demographic, anthropometric, environmental, dietary and healthcare-related variables were found to be associated with the risk of dehydrating diarrhoea. 4 6 Numerous studies have shown that oral rehydration therapy (ORT) with oral rehydration salt (ORS) cures dehydration and prevents death Although 95 per cent of mothers knew about ORS in Bangladesh, 11 more than a quarter of deaths in under-fives are associated with diarrhoea. 12 Little is known about the factors that predispose to dehydration in spite of access to ORS. 11 It becomes imperative to look into the factors that underly the development of life-threatening dehydration from diarrhoea, so that the health workers can identify such children early and keep them under close surveillance and take necessary interventions to alter Acknowledgements The financial support provided by Bangladesh Medical Research Council (BMRC) in conducting this study is gratefully acknowledged. Correspondence: Dr Farid Uddin Ahmed, Associate Professor (Pediatrics), Chittagong Medical College/Hospital, Chittagong- 4000, Bangladesh. the course. This study aims to identify the risk factors associated with dehydrating diarrhoea in children. Materials and Methods This was a prospective case-control study. The study was conducted at the Pediatric Department, including the ORT Corner, of Comilla Medical College Hospital, Bangladesh during It is a 500-bed teaching hospital with a catchment population of 10 million people. The children were selected from the diarrhoea patients who attended the ORT Corner and were admitted to the pediatric ward. The selection was restricted to under-2-year-olds considering their greater vulnerability for mortality and morbidity. The other inclusion criteria were (a) history of acute watery diarrhoea for less than 7 days, and (b) residence in the Comilla district. The cases were eligible children with severe or some dehydration. The controls were children with no signs of dehydration who met the inclusion criteria. The controls were selected to match the cases, two controls per case, by age, i.e. 0 5, 6 11, 12 17, and months using a systemic sampling scheme. The sample size was estimated using EPI INFO-6 statistical package, using a 10 per cent prevalence of dehydration amongst the cases (Diarrhoea), a confidence level of 95 per cent (1 ), and a power (1 ) of 80 per cent. The sample size with a ratio of 1: 2 for case: control showed a requirement of 63 cases and 126 controls. Considering a drop-out rate of 20 per cent, the required sample size for case and controls was taken to be 80 and 160, respectively. Journal of Tropical Pediatrics Vol. 48 October 2002 Oxford University Press

2 The status of dehydration (no sign of dehydration, some and severe dehydration) was assessed as per the WHO recommended criteria and a child was considered to have received ORT, if ORS and recommended home fluids were taken at home. 13 All the cases were admitted to the pediatric ward and the controls were sent back home after treatment at the ORT Corner. After enrollment, each child was examined and their mother was interviewed using a pretested semistructured questionnaire. The weight after rehydration was recorded for nutritional status. The cases and controls were followed at home on the 14th day of illness. At home the interviewer checked the progress of recovery and direct observation was made about the hygienic practices, type of housing, source of water and type of latrine. The home interviewer was not made aware of information collected at hospital. Data was processed using EPI INFO-6 and SPSS/PC statistical package. The odds ratio (OR) was calculated, and the stepwise logistic regression analysis was performed to identify the factors associated with the development of dehydration. Sensitivity and specificity were the key measures to decide the best fitted model. Results The age was the matching character of cases and controls and no significant difference was found. Amongst the cases, 20 (25.0 per cent) had severe dehydration and the rest 60 (75.0 per cent) had some dehydration on admission. Seventy-one (89.0 per cent) cases and 155 (97.0 per cent) controls were cured from diarrhoea at follow-up and the rest 9 (11.0 per cent) cases and 5 (3.0 per cent) controls developed persistent diarrhoea. The cases were at higher risk of developing persistent diarrhoea (OR, 3.93; 95 per cent CI, ; p < 0.01). The episode duration was 8.01 ± 2.30 days; for cases and controls duration was 9.63 ± 1.94 and 7.27 ± 2.07 days, respectively, and the difference was significant (p < 0.001). Table 1 shows the sociodemographic characteristics of children of cases and controls. The characters associated significantly with the development of dehydration were education, occupation and socioeconomic condition of parents, and child death in the family (p < ). The clinical profile of cases and controls are shown in Table 2. The diarrhoeal duration on the day of attendance at hospital, frequency of stool per day, vomiting by the child, ORT and drugs at home and nutritional status were found to be associated significantly with dehydration (p < ). The mean stool frequency per day was ± 8.36 for cases and 8.43 ± 2.75 for controls (p < 0.001). ORT at home was received by 96.2 per cent of cases, which includes all of the severely dehydrated and 95.0 per cent of some dehydrated, in contrast to 70.6 per cent of controls. The quantity of oral rehydration fluid (ORF) intake differed significantly between cases TABLE 1 Sociodemographic characters of cases and controls Characteristics Case (%) Control (%) p Odds ratio Mean age (months) NS Male child 57 (71.3) 93 (58.1) NS Mothers age (years) ± ± 5.13 NS (mean ± SD) Fathers age (years) ± ± 6.7 NS (mean ± SD) Illiterate mother 54 (67.5) 72 (45.0) < ( ) Illiterate father 45 (56.3) 55 (34.4) < ( ) Working mother 18 (22.05) 34 (21.3) NS Fathers doing manual work 45 (56.3) 55 (34.4) < ( ) Poor socioeconomic 36 (45.0) 50 (31.3) < condition ( ) Mean family members 6.50 ± ± 2.53 NS More than two child family 37 (46.3) 53 (33.1) NS More than one under-5 child 39 (48.8) 80 (50.0) NS in family Child death in family 21 (26.3) 19 (11.9) < ( ) Fathers staying home 72 (90.0) 140 (87.5) NS 260 Journal of Tropical Pediatrics Vol. 48 October 2002

3 TABLE 2 Clinical profile of cases and controls Clinical profile Cases (%) Controls (%) p Odds ratio Duration of diarrhoea at 47 (58.8) 69 (43.1) < hospital attendance (> 3 days) ( ) Stool frequency more than 5/day 78 (97.5) 138 (86.3) < ( ) Vomited during episode 77 (96.4) 49 (30.6) < ( ) Received ORT at home 77 (96.2) 113 (70.6) < ( ) ORT started after passing more 46 (59.7) 75 (65.8) NS than three stools Mean time passed before starting 7.64 ± ± NS ORT (h) Oral rehydration fluids (ORF) 1395 ± 1083 ml 680 ± 464 ml < 0.01 intake per day at home Drugs received before attending 30 (37.5) 21 (13.1) < hospital ( ) Previous admission of index child 32 (40.0) 64 (40.0) NS in hospital Wasted child 19 (23.7) 12 (7.5) < ( ) Breastfeeding 75 (93.7) 154 (96.3) NS Inappropriate feeding practice 23 (28.8) 37 (23.1) NS Inappropriate primary vaccination 14 (17.5) 14 (8.8) NS TABLE 3 Environmental factors possessed by cases and controls Factors Cases (%) Controls (%) p Odds ratio Distance from hospital (> 3 km) 36 (45.0) 22 (13.75) < ( ) Thatched house 25 (31.3) 31 (19.4) < ( ) Unclean courtyard 75 (93.8) 148 (92.5) NS No sanitary latrine 31 (38.8) 44 (27.5) NS Drinks safe water 80 (100.0) 160 (100.0) NS Use unsafe water for household 30 (37.5) 55 (34.4) NS purpose Wash hands only with water 73 (91.3) 146 (91.3) NS before eating Wash hands only with water 12 (15.0) 11 (6.9) NS after passing stool Mother s dirty fingernails 60 (75.0) 72 (45.0) < ( ) Child s dirty fingernails 68 (85.0) 82 (51.3) < ( ) Owning no refrigerator 75 (93.7) 131 (81.8) < ( ) Ate unsafe leftover food 66 (82.5) 112 (70.0) < ( ) Journal of Tropical Pediatrics Vol. 48 October

4 TABLE 4 Logistic regression analysis for predictors of dehydration Variables SE Wald df Sig R Exp(B) Vomited during episode ORT given at home Mother s dirty fingernails Distance from hospital (more than 3 km) Constant Model 2 = , df = 4, p < and controls (1395 ml vs. 680 ml). Feeding practices were not associated with the development of dehydration. Breastfeeding was practised by and 96.3 per cent of mothers of cases and controls, respectively. It is evident from Table 3 that the environmental factors that have a significant difference between cases and controls are: distance from hospital; type of house; dirty fingernails of mothers and children; owning no refrigerator; and practice of eating unsafe leftover foods. A total of 17 factors were found to be associated significantly with the development of dehydration. The OR and the 95 per cent CI were calculated. These 17 factors were analysed with step-wise logistic regression model and the last step is shown in Table 4. A combination of vomiting by the child, ORT at home, mothers dirty fingernails, and residence more than 3 km from the hospital was found to be the best-fit model and provided the maximum sensitivity (77.5 per cent) and specificity (91.2 per cent) for predicting the development of dehydration from diarrhoea. The -coefficients indicated that the most significant factor influencing dehydration was vomiting. Discussion Dehydration is a major cause of hospital admission and death due to diarrhoea in young children. The main results of the study are shown in Table 4. This model has a sensitivity of 77.5 per cent and a specificity of 91.2 per cent for the prediction of development of dehydration in children with diarrhoea. The presence of vomiting in a child before attendance puts a child at 58 times higher risk of developing dehydration. Many mothers stopped the use of oral fluid completely when patients vomited, 14 despite the fact that vomiting does not prevent successful ORT. ORT is the keystone of management of acute diarrhoea for the prevention and treatment of dehydration. 15 It is simple, highly effective, inexpensive and technologically appropriate. 15,16 In this study it was found that all of the severely dehydrated cases, 95.0 per cent of the some dehydrated cases, and 70.6 per cent of controls (no signs of dehydration) practised ORT at home, indicating that the practice of ORT was influenced by the severity of dehydration. An intake of about 1400 ml/day of ORF was recorded for the cases. None of these practices could prevent the development of dehydration but rather put the cases at increased risk. To make ORT effective it needs to be appropriate for the cases; the method of giving, the preparation of the solution, and the quantity has to be correct. ORT is inappropriate in cases with severe dehydration, persistent vomiting and high purging. 13 The study findings supported the reasons for ineffective ORT as 25.0, 96.4 and 97.5 per cent of cases had severe dehydration, vomiting and high frequency of stool, respectively. Ahmed, et al. 11 found that vomiting and incorrect method of giving ORT limited the intake of oral fluids. They also reported that incorrect preparation of ORS solution increased significantly the refusals by the child, thereby limiting the intake, which is also an additional reason of ineffective ORT amongst the cases. 17 The significantly higher intake of ORF can also be explained by the severity of the cases which might stimulate the mothers to give more fluids. This does not mean that the child received the required amount as the mothers might be ignorant about the quantity of fluids required for rehydration. 11 The amount received seemed to be inadequate. All these indicated the mothers poor case management knowledge, which eventually puts the child at higher risk for the development of dehydration, in spite of practising ORT. There is also a suggestion that the mothers were not properly instructed by health personnel about ORT. All patients in our study were young children being cared for by their mothers. The role of the mother in influencing the severity of the diarrhoeal episode is indicated by the association between dirty fingernails of the mother and the presence of severe or moderate dehydration. Studies have shown that enteric infections can spread via contaminated hands 262 Journal of Tropical Pediatrics Vol. 48 October 2002

5 and fingertips 18,19 and the risk of spreading enteric pathogen to young children from the hands of the attendants who care for them is stressed repeatedly. 18,20,21 The dirty fingernails of children and the serving of unsafe leftover foods also reflected poor maternal hygienic practices. The children were found to be at four times higher risk of developing dehydration when any drug was received. In fact drugs prolonged the duration of diarrhoea 22 and put the child at risk again of developing dehydration. Several investigators had reported that non-breastfed infants were at more risk of developing severe diarrhoea and the lack of association in this study might be due to universal breastfeeding practices among cases and controls. Predictors, such as vomiting, ORT, mother s dirty fingernails, and residence of the child away from the hospital will be helpful in identifying the children at risk of developing dehydration and could be used by the community health workers. The promotion of effective ORT practice, which includes preparation of ORT fluids, method of feeding fluids, amount to be fed and how to continue it during vomiting, as well as hygienic practices of hand washing by mothers through health education, could reduce the incidence of and prevent dehydration from diarrhoea. References 1. Snyder JD, Merson MH. The magnitude of the global problem of acute diarrhoeal diseases: A review of active surveillance data. Bull WHO 1982; 80: Bern C, Martines J, Zoysa ID, Glass RI. The magnitude of the global problem of diarrhoeal diseases: a ten year update. Bull WHO 1992; 70: Black RE, Lopez de Romana G, Brown KH, et al. Incidence and etiology of infantile diarrhoea and major routes of transmission in Huascar, Peru. Am J Epidemiol 1989; 129: Victora CG, Kirkwood BR, Fuchs SC, Lombardi C, Barros FC. Is it possible to predict which diarrhoea episodes will lead to lifethreatening dehydration? 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