(A) study of estimation of total number of leprosy patients in 1968
Authors
김계한
Issue Date
1969
Description
의학과/박사
Abstract
[한글]
[영문]
Since significant progresses have been attained in recent years in Korea, i.c., the installation and reorganization of leprosy institutions, the abolishment of doctrine of previous compulsory insitutionization of leprosy patient and initiation of resultandt domiciliary treatment on out-patient status through special skin
clinics and others, organization and field activities of leprosy mobile teams, and a large scale resettlement of ex-leprosy cases for their social rehabilitation, it became more and more evident that a total number of leprosy patients has to be estimated, accurately as far as possible, by some of rational approach.
So far, numerous reports have been made from time to time on the estimation of total number of leprosy patients in Korea. However, there existed great differences between numbers of leprosy patients estimated by them, owing mainly due to the fact
that none of such estimations was made by any of rational approach in methodology.
In the first part of this study, it was attempted to estimate a total number of leprosy patients by 1968 on the basis of data obtained from Wolsung-Gun total population survey for leprosy case finding, and of prevalence rate in cities and Guns established from distribution density of known leprosy patients by 1965.
In the second part, the estimation of unknown leprosy cases in 3 cities and 92 Guns in Chungchung, Chollar and Kyungsang Provinces was made from the data obtained through mass survey by leprosy mobile teams and leprosy case workers in these areas, and this figure was compared with the one with was obtained from the first part of this study.
Materials and methods
A. Estimation of total numbers of leprosy patients by 1968 on the basis of data obtained from Wolsung-Gun total population survey for case finding and prevalence rate in cities and Guns established from distribution density of known leprosy patients by 1965.
1. Total population survey in Wolsung-Gun for case finding.
The Wolsung-Gun is one of the well-known high endemic area of leprosy in Korea(Kim et al., 1959; Lew, 1961; Suh, 1964; Choi, 1965), and the Gun was selected for total population survey, according to WHO recommendation(WHO, 1966), to conduct overall detection of unknown leprosy cases in this area.
The population of Wolsung-Gun was 189, 995 in 1965 and total population survey was carried out by 5 mobile teams through April, 1963 to the end of 1965.
Case finding methods applied in Wolsung-Gun survey were 1) by out-patient skin clinic, 2) by mass survey(door to door), 3) by school children examination, 4) by notification, 5) by contact survey, 6) by voluntary attendance and 7) on the way.
Diagnosis of leprosy patient was made on clinical symptomatology and bacteriological examination of skin smears.
From this survey, the detection rate i.c., number of newly detected leprosy cases per 1,000 population in Wolsung-gun, was determined.
2. Establishment of prevalence rate in cities and Guns.
Careful distribution of 33,531 known leprosy cases in 1965 by their birth place was made, and the prevalence rate in a given city or Gun ws established from number of known leprosy cases per 1,000 of the population in each area.
3. Estimation of number of unknown leprosy cases in cities and Guns.
The ratio of the detection rate in Wolsung-Gun(derived from the total population survey) to the prevalence rate in Wolsung-Gun (obtained from distribution density in Wolsung-Gun of known leprosy cases in 1965) was designated as Estimation Proportionate. The prevalence rate of cities and Guns multiplied by Estimation Proportionate in the estimated detection rate for unknown leprosy cases in each area.
Finally, estimated number of unknown leprosy cases in each city or Gun is readily obtained from multiplying the total population of the local by the estimated detection rate for unknown leprosy cases in that area.
4. Estimation of total number of leprosy patients by 1968 in Korea.
The total number of leprosy cases by 1968 in Korea was estimated by addition of 1) a total number of known, registered leprosy cases by 1968, 2) a total number of estimated unknown cases, 3) numbers of possible leprosy cases which might have developed among house-hold contacts of known lepromatous leprosy patients(WHO, 1966; Kim et al., 1968; Ministry of Health and Social Affairs, 1968b), and 4) number of leprosy cases which was not included in the estimation of a total number of unknown cases because of failure in identification of birth place of know
leprosy cases during the process of establishing the prevalence rate in each city or Gun.
B. Estimation o number of unknown cases in Chungchung, Cholla and Kyungsang Provinces on the basis of data obtained from mass survey by leprosy mobile teams and leprosy case workers.
From January 1966 to September 1968, 12 leprosy mobile teams and 102 leprosy case workers conducted mass survey for the detection of unknown leprosy cases in 3 cities and 92 Guns throughout Chungchung, Cholla and Kyungsang Provinces.
The methods applied in case finding were 1) by contact survey and 2) by notification in early part, and 3) by mass survey in later part of these activities.
Suspicious leprosy cases identified by leprosy case workers during mass survey were further confirmed by the doctor of each mobile team assigned to each survey area.
From this mass survey, the detection rate of unknown cases by mass survey per 1,000 population was developed, and number of unknown cases in a given city or Gun was estimated by multiplying the total population of the area by the detection rate derived from mass survey.
Comparison was made between the number of unknown leprosy cases in 3 cities and 92 Guns estimated from the data obtained by leprosy mobile teams and leprosy case workers and the one estimated from the data of Wolsung-Gun total population survey
and the prevalence rate in cities and Guns derived from distribution density of known leprosy cases in 1965.
Results and Summary
In an attempt to achieve an accurate estimation of total number of leprosy cases by 1968, estimation was made, as a rational approach, on basis of data(detection rate of unknown cases) from total population survey for case finding in Wolsung-Gun, and prevalence rate derived from distribution density of known leprosy patients in 1965 by their birth place. The applicability of this approach is evaluated by comparing the number of estimated unknown cases in Chungchung, Cholla and Kyungsang Provinces derived from mass survey by leprosy mobile teams with the one derived from Wolsung-Gun survey and prevalence rate.
1. The ratio of the detection rate of unknown leprosy cases in Wolsung-Gun total population survey to the prevalence rate of Wolsung-Gun derived from distribution density by their birth place of 33,531 known leprosy cases in 1965 was 0.6155, and
this figure was designated as Estimation Proportionate.
Estimated detection rate of unknown cases in each city and Gun was calculated from multiplying the prevalence rate of each city or Gun by Estimation Proportionate.
Estimated number of unknown leprosy cases in a give city or Gun was obtained from multiplying total population of the area in 1968 by the estimated detection rate.
The sum of the estimated numbers of known leprosy cases in cities and Guns was 20,232.
2. A total number of leprosy patients in Korea by 1968 is estimated to be 60.157 which is the sum of 1) 37,571; a total number of known, registered leprosy cases by 1968, 2) 20,232; a total number of estimated unknown cases, 3) 1,454; number of
leprosy cases which was not included in the estimation of a total number of unknown cases because of failure in identifying their birth place, and 4) 900; numbers of possible leprosy cases among the house-hold contacts of lepromatous leprosy patients.
3. Mass survey by leprosy mobile teams and leprosy case workers in Chungchung, Cholla and Kyungsang Provinces(3 cities and 92 Guns) from January 1966 to September 1968 resulted in the estimation of unknown leprosy cases in these areas to be
21,516.
This figure was higher by 4,827 than 16,689, which was the number of unknown cases in these areas estimated from the data of Wolsung-Gun total population survey and the prevalence rate in cities and Guns derived from distribution density of known leprosy cases in 1965, and the number was regarded as th maximum ceiling of total number of unknown cases in these areas.