Analysis of Urinary Mass Screening for Second Grade of Elemantary School Children in Paju City

파주 지역 초등학교 2학년생에게 실시된 집단 뇨검사 분석

Purpose We performed urinary mass screening(UMS) program for 2,804 children of second grade elemantary school 8 years of age in Paju city with cooperation of Paju City Health Center to determine the prevalence of asymptomatic proteinuria and hematuria, and to estimate the risk of incipient renal diseases. Also we attempted to evaluate the significance of hematuria in UMS in addidtion to proteinuria. Methods : 2,804 children of the 2nd grade of elementary school who lived in Paju city were included to our UMS program in 2000. They were constituted with 1,428 boys and 1,376 girls. The screening program was carried out in 3 steps The 1st screenig test was performed at schools and then students with abnormal results were examined repeatedly at Paju City Health Center and our hospital. Those students who showed proteinuria and/or hematuria in the 1st and 2nd test were referred to our hospital to undertake the 3rd close examination including physical examination, laboratory tests and radiologic tests. Results : (I) The prevalence of urinary abnormality in the 1st screening test was $8.3\%$(233 students), comprised of $5.9\%$ of boys, $10.8\%$ of girls. (2) Among 2,804 children tested in the first screening, prevalences of asymptomatic proteinuria and isolated hematuria were 64($2.3\%$), 163($5.8\%$) respectively, and the prevalence of proteinuria with hematuria was 6($0.2\%$). (3) Among 233 students with urinary abnormalities at the 1st screening test, 102 students applied to the 2nd test. 32 children, about one third of them, were also found to have abnormal urinary findings ; isolated hematuria 30, proteinuria with hematuria 2. (4) Those findings of clinical evaluation for children with isolated hematuria at the hospital showed as follows: idiopathic isolated microscopic hematuria 21, normal 6, urinary tract infection 1, idiopathic hypercalciuria 1 and simple renal cyst 1. Those 2 students with proteinuria and hematuria seemed to have chronic glomerulonephritis. Conclusion : (1) The clinical evaluation for children who showed positive results at the 1st screening test should be done judiciously. Because of high false positive rate, almost who showed positive results was normal, only a few of them had pathologic conditions. In this study, actual incidence of incipient renal diseases in children of 8 year old was calculated to be $0.4\%$. (2) The definite conclusion whether a urinary mass screening test can alter the prognosis of incipient renal diseases could not be drawn with this study. Further study must be necessary (3) We could acknowledge the significance of hematuria in UMS, but it is necessary that one should be judicious in managing and follow-up those that show abnormal results. (J Korean Soc Pediatr Nephrol 2001;5 : 156-63)

목 적 : 본 연구의 목적은 집단뇨검사의 대상으로 8세 전후의 어린이가 포함되는 것이 타당한지 또한 혈뇨 검사를 집단뇨검사에 포함시키는 것이 실효성이 있는지를 알아 보고자 하였다. 대상 및 방법 : 파주 지역 초등학생 2,804명을 대상으로 모두 3차에 걸쳐 단계적 요검사와 정밀 검사를 실시하여 단백뇨와 혈뇨의 유병율을 조사하였다. 요검사 이상자를 대상으로 정밀 검사를 시행하여 실제 신질환의 유병율을 알아보고 집단뇨검사의 유용성을 검증하였다. 결 과 : 파주 지역 초등학생 8세군에서 나타난 무증상 요검사이상 유병율은 $8.3\%$로 각각 단백뇨 $2.3\%$, 혈뇨 $5.8\%$였고 혈뇨와 단백뇨를 동시에 보인 경우는 $0.2\%$로 조사되었다. 1차 선별 검사 이상자 233명중 102명이 2차 검사에 응하여 이들 중 약 1/3인 32명이 다시 양성자로 나타났고 혈뇨가 $41.7\%$, 단백뇨가 $0\%$, 동시에 양성인 경우가 $66.7\%$로 2차 검사에 이상자로 확인되었다. 3차검사에 응한 32명중 30명은 단독 혈뇨증을 보였고 2명은 혈뇨와 단백뇨가 동시 확인되었다. 이들 단독 혈뇨증을 보인 30명 중6명은 정상으로 나타났고, 21명은 특발성 단독 현미경적 혈뇨, 나머지 3명은 요로감염증 1명, 특발성 과칼슘뇨증 1명, 단순 신낭종 1명로 확인되었다. 혈뇨와 단백뇨를 동시에 보인 2명은 만성 사구체 신염을 가지고 있는 것으로 생각되었다. 결 론 : 본 연구의 집단뇨검사에서 단백뇨와 혈뇨의 유병율 $2.3\%,\;5.8\%$로 조사되었고 이들 중 대부분이 정상으로 나타나 집단뇨검사의 특이성이 낮은 것을 알 수 있었다. 검사 대상에 8세군을 포함시키는 문제에 관해서 본 연구에서 비교적 높은 양성율을 보였다는 점을 감안하면 집단뇨검사에 8세군을 포함하는 것이 타당하다고 생각되었다.