J Egypt Public Health Assoc
Vol. 83 No. 3 & 4, 2008
Indicators of the Screening Program for Congenital Hypothyroidism in Alexandria Nihad I. Dabbous*, Hanan M. Abde El-Aziz*, Nagwa Y. Abou El– Enein**, Hisham H. Kandil***, Ahmed A. El-Kafoury* * Department of Family Health, High Institute of Public Health, Alexandria ** Department of Health Administration and Behavioral Sciences, High Institute of Public Health, Alexandria. *** Treating Center of the Screening Program for Early Detection of Congenital Hypothyroidism, ABSTRACT The screening of newborn children for metabolic and endocrinological disorders is one of the unsung successes of the health service. This study aimed to evaluate the congenital hypothyroidism (CH) screening program in Alexandria in terms of coverage, effectiveness of detecting and managing the cases. A record review was conducted at the Information and Decision Making Support Center of Alexandria Health Directorate during the period from October 2000 to December 2003 to evaluate the coverage of the program and to detect the number of true positives and false positives used to calculate the positive predictive value of the screening test. A follow- up study was conducted at the pediatric clinic of the Student's Sporting Hospital for all positive cases detected by the (CH) screening program attending the clinic for diagnosis, confirmation and treatment during the year 2002 (30 cases were followed-up) . The percentage of program coverage was 49.4%, 63.3% and 77.6% in the years 2001, 2002 and 2003 respectively. The total positive cases in the three years were 26, 30, and 14 with positive predictive value of 65%, 57%, and 64% respectively. About three-quarters (73.3%) of all positive cases (30 cases) were compliant to therapy. Compliance was on fixed times in more than half of cases (56.7%), and irregular in 40%. There was a positive trend of increase in program coverage and Corresponding Author: Dr. Hanan Mourad Department of Family Health, High Institute of Public Health, University of Alexandria, Alexandria, Egypt. Email:
[email protected]
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effectiveness in detecting and managing the cases through the three years of the study. Key words: Newborn screening, congenital hypothyroidism, evaluation, effectiveness, false positives, positive predictive value. INTRODUCTION Health improvement is what public health professionals strive to achieve. To reach this goal, we must devote our skills and
will to evaluate the effects of public health actions.
Program evaluation is an essential organizational practice in public health however, it is neither practiced consistently across program areas, nor is it sufficiently well-integrated into the dayto-day management of most programs.(1) The WHO defined evaluation as “A systematic way of learning form experience and using the lessons learnt to improve current activities and promote better planning by careful selection of alternatives for future action".(2) The screening of newborn children for metabolic and endocrinological disorders is one of the unsung successes of the health service. The screening program enables potentially devastating diseases to be detected at a very early stage and allows treatment to be started immediately at a stage before any significant
damage
takes
place.(3)
Newborn
screening
for
congenital hypothyroidism is the first and perhaps the most successful
example
of
population-wide
screening
testing.
Performed within the first few days of life, drops of blood are collected from a newborn's heel and are sent to a central laboratory for analysis.(4) The primary objective of each newborn screening system is to ensure that every newborn receives appropriate services. Public health agencies have a responsibility to ensure the quality of the newborn screening system.(5)
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The integration of information systems would allow newborn screening program evaluation to take place with more ease. Ideally, the information obtained by a newborn screening program would allow the description of: the number and percent of children adequately screened, with appropriate follow-up, with false-positive and false-negative results, with specific diagnoses, and with appropriate care. Important information include also the time between the newborn screen and the initiation of treatment, the long-term improvement in health status occurring as a result of screening, follow-up, diagnosis, and treatment. In addition, the number of children diagnosed with a condition missed by the screening programs and, where possible, an assessment of the reasons they were missed, and the number and percentage of children lost to follow-up can be obtained.(6) The neonatal screening service involves the close cooperation of families, health professionals, and administrative staff in a range of locations. Because the screened conditions are rare and the consequences of missing them are so serious, it is important to have clear quality assurance measures to ensure that the service is running in the most effective, efficient, equitable and humanitarian way possible.(7) The Egyptian Ministry of Health and Populations (MOHP) endorsed the introduction of screening program for CH using the TSH assay method. In Alexandria the program started since October 2000 in 7 Health centers affiliated to the MOHP representing the different districts of Alexandria. This study aimed to evaluate the congenital hypothyroidism screening program in Alexandria in terms of coverage and effectiveness of detecting and managing the cases.
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MATERIAL AND METHODS The
study
was
carried
out
through
follow-up
and
retrospective approaches at the pediatric clinic of the Students’ Sporting Hospital for positive cases detected by the screening program attending the clinic for diagnosis, confirmation and treatment (30 cases were followed-up) a record review of the computer database in the Information and Decision Making Support Center of Alexandria Health Directorate was also carried out. A structured interview questionnaire with mothers of all positive cases coming for regular follow- up and
receiving
treatment for CH in Sporting Students’ Hospital was designed to collect data about history of signs and symptoms of CH before and after treatment, compliance to therapy, scheduled follow up visits and investigations. All positive cases were subjected to complete physical examination including measuring the weight, height or recumbent length and the head circumference. The Z score for weight/age, height /age, weight/height was calculated. The Griffiths Mental-Developmental Scales: birth to 2 years (GMDS 0-2) was used for the assessment of mental development. GMDS measures, five areas of development: locomotor, personalsocial, hearing and speech, eye and hand co-ordination, and performance. The total developmental quotient (DQ) and subquotients were calculated as described in the manual(8) ‘‘normal’’ DQ was defined as >87. These cases were followed- up for more than 6 months. The records of the pediatric clinic in the Students’ Sporting Hospital and the child insurance book were reviewed for screening results including age at screening, confirmation, and
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age at starting treatment, extent of investigation, the number of follow up visits and compliance to therapy. The computer database in the Information and Decision Making Support Center of Alexandria Health Directorate were reviewed from October 2000 to December 2003 to calculate the number of: live births, screened infants, and the health centers applying the program. In addition, the number of total positives, true positives and false positives were recorded to calculate the positive predictive value of the screening test. These data were used to estimate the coverage of the program.
RESULTS Table (1) shows the program indicators in the years 20012003. In the year 2001 the number of live births was 88446, the screened infants were 43641 with a percentage of coverage about 50 %.The total positive cases were 26 with 9 false positives, and a positive predictive value of 65.4%. The incidence of primary CH among screened infants was 1:2567. The number of health units applying the program was 14. False positive rate among screened infants was 0.020%. In the year 2002, the number of live births and the screened infants increased (88728 & 56202), so the percentage of coverage increased to 63.3%. The total positive cases were 30, and only 17 were true positive with a positive predictive value of 56.7%. The incidence of primary CH among screened infants was 1:3306. More health units applied the program (44).False positive rate among screened infants increased to 0.023%. In the year 2003 the percentage of coverage was 77.6 % with 91573 live births and 71038 screened infants. The total positive
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cases were 14 with only 9 true positive cases and the positive predictive value was 64.2%. The incidence of primary CH among screened infants was 1:7893. The number of health units applying the program was 64. False positive rate among screened infants was 0.007% Table (1): Program Indicators: The Percentage of Coverage and Positive Predictive Values in the Year 2001, 2002 and 2003. The indicator
2001
2002
2003
Total
Total number of live births
88446
88728
91573
268747
Screened infants
43641
56202
71038
170881
Percentage of coverage
49.4
63.3
77.6
63.58
Number of health units applying the program
14
44
64
64
Total positives
26
30
14
70
True positives
17
17
9
43
False positives
9
13
5
27
Positive predictive value
65.4%
56.7%
64.2%
61.4%
Incidence of primary CH
1:2567
1:3306
1:7893
1:3974
0.020 %
0.023 %
0.007%
0.016%
among screened infants False positive rate among screened infants
Table (2) reveals that, infants who underwent screening in the 1st week of life were about four fifths ( 83.3%) of cases and after 7 days were 16.7% . Regarding age at serum sampling, it was in the 1st week in 13.3% of cases and it ranged between the seventh and thirteenth day in about three fourths of cases (76.7%). The age at confirmation was between the seventh and thirteenth day in 73.3% of cases. It was between 14 and 20 days in 20% and was delayed after the 3rd week in only 6.7% of cases. Age of start of therapy was in the 2nd week of life in nearly half of cases (46.7%), in the 3rd week in 40% and after 21 days in 10%. About three-quarters of positive cases were always compliant to therapy (73.3%) but nearly one quarter (26.7%)
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were not. The compliance was on fixed times in more than half of cases (56.7%), was irregular in 40% and was never on scheduled times in 3.3%. As regards the compliance to scheduled visits, most of patients (83.3%) were always compliant and less than one fifth (16.7%) were sometimes compliant. The patients were always compliant to investigations in most of cases (93.3%) and only 2 of them (6.7%) were not always compliant. Table (2): Distribution of Positive Cases According to Age at Screening, Serum Sampling, Confirmation, Start of Therapy and Compliance. Positive cases Age at screening 7 Mean of 5.66 ±2.67days Age at serum sampling 71421+ Mean of 9.4±3.78 days Age at confirmation 71421+ Mean 12 ±3.93 days Age at start of therapy 71421+ Unknown Mean 14.79 ±5.15 days Compliance to therapy Always Sometimes Compliance to therapy in fixed time Always Sometimes Never Compliance to scheduled visits Always Sometimes Compliance to investigations Always Sometimes
N=30
%
25 5
83.3 16.7
27 2 1
90.0 6.7 3.3
22 6 2
73.3 20.0 6.7
14 12 3 1
46.7 40.0 10.0 3.3
22 8
73.3 26.7
17 12 1
56.7 40.0 3.3
25 5
83.3 16.7
28 2
93.3 6.7
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As regards the second clinical assessment, the patient's age ranged from 6 months to more than 36 months. A similar percent (23.3%) were between 18 to less than 24 months and 30 to less than 36 months. Only 10% were less than one year. Most of patients (83.4%) were always compliant to therapy and only 10% were not always compliant. The compliance to medicine on timed schedule was “always” in 40% of cases but was “not always” in 56.7%. The compliance to scheduled visits was as high as 93.3%. Most of patients (83.3%) were always compliant to investigations. The number of visits in the 1st year ranged from less than 5 to more than 15 times. In more than half of the cases (56.7%) the number of visits ranged between 5 and 9, and it was more than 15 in 16.7%. As regards the number of visits in the 2nd year, it was between one and 4 in 36.7% of cases, between 5 and 9 in 30% and in one third of cases (33.3%) could not be defined. (Table 3) For the symptoms of congenital hypothyroidism in positive cases before and after the initiation of therapy, table (4) reveals that there was statistically significant difference between before and after treatment regarding constipation, lethargy and prolonged neonatal jaundice (p= 0.045, 0.013, and 0.000 respectively).
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Table (3): Distribution of Positive Cases According to Their Age at Second Visit, Compliance to Therapy, Scheduled Visits and Investigations. Positive case
Age at second visits (in months) 61218243036Compliance to therapy Always Sometimes Never Treatment stopped Compliance to medicine in fixed time Always Sometimes Treatment stopped Compliance to scheduled visits Always Sometimes Compliance to investigations Always Sometimes Number of visits in the first year of age 151015Mean 8.96±3.19 Number of visits in the second year of age 15-10 Patients still < 2 years Mean 4±2.60
N=30
%
3 6 7 5 7 2
10.0 20.0 23.3 16.7 23.3 6.7
25 3 1 1
83.4 10.0 3.3 3.3
12 17 1
40.0 56.7 3.3
28 2
93.3 6.7
25 5
83.3 16.7
2 17 6 5
6.6 56.7 20.0 16.7
11 9 10
36.7 30.0 33.3
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Table (4): Distribution of Signs and Symptoms of (CH) Before and After Treatment. Symptoms and signs
Constipation Yes No Unknown Feeding problems Yes No Unknown Lethargy Yes No Unknown Respiratory distress Yes No Umbilical hernia Yes No Enlarged tongue Yes No Facial puffiness Yes No Hoarse cry Yes No Unknown Neonatal Jaundice Yes No Unknown
Before treatment No. %
After treatment No. %
11 17 2
36.7 56.7 6.6
4 26 0
13.3 86.7 0
2 28 0
6.7 93.3 0
1 27 2
3.3 90 6.7
9 20 1
30.0 66.7 3.3
1 28 1
3.3 93.4 3.3
2 28
6.7 93.3
0 30
0.0 100.0
0 30
0 30
0 30
0.0 100.0
1 29
3.3 96.7
0 30
2 28
6.7 93.3
1 28 1 16 13 1
χ2
P
4
0.045*
0.000
1.000
6.13
0.013*
0.5
0.479
0.0 100.0
0.000
1.000
0 30
0.0 30.0
0.5
0.479
3.3 93.3 3.3
0 30 0
0.0 100.0 0.0
0.000
1.000
53.3 43.4 3.3
0 30 0
0.0 100.0 0.0
14.06
0.000*
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As regards the Z score for weight /age, in the first clinical assessment, only one male scored
