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Volume 37(4); November 2004
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Review
Air Pollution Exposure and Health Effects in Fetus.
Bo Eun Lee, Hye sook Park, Young Ju Kim, Eun Ae Park, Yun Chul Hong, Eun Hee Ha
J Prev Med Public Health. 2004;37(4):291-299.   Published online November 30, 2004
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AbstractAbstract PDF
As there have been growing concerns about the adverse effects of air pollution on birth outcome, studies for this area has been carried out in different populations and sites. We reviewed the epidemiologic studies that evaluated the effects of air pollution on birth outcome such as low birth weight and preterm births. We identified the air pollution exposure during pregnancy was related with low birth weight and preterm birth, although there are differences among studies for the critical period of vulnerability. The biological mechanisms whereby air pollution might influence health of fetus are not clearly established. The exposure to carbon monoxide (CO) during pregnancy could increase fetal carboxyhemoglobin and result in tissue hypoxia. On the other hand, ambient particles less than 10 micrometer in aerodynamic diameter (PM10) could lead to inflammation and increase blood viscosity. Controlling for potential confounders and valid assessment of exposure are the methodological issues remained in these epidemiologic studies. In the future, more studies are needed to investigate the effect of air pollution on preterm birth or stillbirths, considering the various exposure period and the biological mechanism.
Summary
Original Articles
Prenatal Exposure to PM10 and Preterm Birth between 1998 and 2000 in Seoul, Korea.
Eun Hee Ha, Bo Eun Lee, Hye Sook Park, Yun Sang Kim, Ho Kim, Young Ju Kim, Yun Chul Hong, Eun Ae Park
J Prev Med Public Health. 2004;37(4):300-305.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVES
The exposure to particulate air pollution during the pregnancy has reported to result in adverse pregnancy outcome such as low birth weight, preterm birth, still birth, and intrauterine growth retardation (IUGR). We aim to assess whether prenatal exposure of particulate matter less than 10 (m in diameter (PM10) is associated with preterm birth in Seoul, South Korea. METHODS: We included 382, 100 women who delivered a singleton at 25-42 weeks of gestation between 1998 and 2000. We calculated the average PM10 exposures for each trimester period and month of pregnancy, from the first to the ninth months, based on the birth date and gestational age. We used three different models to evaluate the effect of air pollution on preterm birth; the logistic regression model, the generalized additive logistic regression model, and the proportional hazard model. RESULTS: The monthly analysis using logistic regression model suggested that the risks of preterm birth increase with PM10 exposure between the sixth and ninth months of pregnancy and the highest risk was observed in the seventh month (adjusted odds ratio=1.07, 95% CI=1.01- 1.14). We also found the similar results using generalized additive model. In the proportional hazard model, the adjusted odds ratio for preterm births due to PM10 exposure of third trimester was 1.04 (95% CI=0.96-1.13) and PM10 exposure between the seventh month and ninth months of pregnancy was associated with the preterm births. CONCLUSIONS: We found that there were consistent results when we applied the three different models. These findings suggest that air pollution exposure during the third trimester pregnancy has an adverse effect on preterm birth in South Korea.
Summary
Placental Superoxide Dismutase, Genetic Polymorphism, and Neonatal Birth Weight.
Yun Chul Hong, Kwan Hee Lee, Moon Whan Im, Young Ju Kim, Eun Hee Ha
J Prev Med Public Health. 2004;37(4):306-311.   Published online November 30, 2004
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AbstractAbstract PDF
BACKGROUND
The roles of antioxidants in the placenta and genetic susceptibility to oxidant chemicals in relation to neonatal birth weight have not been elucidated. We determined whether the level of placental manganese superoxide dismutase (MnSOD) and its genetic polymorphism plays any role in oxidative stress and neonatal birth weight. METHODS: We measured placental MnSOD and determined MnSOD genetic polymorphism among 108 pregnant women who were hospitalized for delivery and their singleton live births in Korea. Main outcome measurements are maternal urinary malondialdehyde (MDA) and birth weight. RESULTS: Maternal urinary concentrations of MDA were significantly associated with neonatal birth weight (P=0.04). The enzyme level of placental MnSOD was also significantly associated with MDA concentration (P=0.04) and neonatal birth weight (P< 0.01). We observed dose-response relationships between placental MnSOD and maternal urinary MDA, and neonatal birth weight after adjusting for maternal weight, height, age, and neonatal sex. After controlling for covariates, MnSOD variant genotype increased maternal urinary MDA concentrations (P< 0.01) and reduced birth weight by 149 gm (P=0.08). CONCLUSIONS: This study demonstrates that the placental level of MnSOD during pregnancy significantly affects fetal growth by reducing oxidative stress, and that genetic polymorphism of MnSOD probably modulate the effects of oxidants on fetal growth.
Summary
Epidemiologic Investigation into the Outbreak of Acute Hemorrhagic Conjunctivitis in Gyeongju-City, South Korea, in 2002.
Hong Hwan Kim, Hyun Sul Lim, Young Sun Min
J Prev Med Public Health. 2004;37(4):312-320.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVES
An outbreak of acute hemorrhagic conjunctivitis (AHC) caused by coxsackie A24 (CA24) virus occurred in South Korea in 2002. CA24 was isolated for the first time from patients with AHC. Therefore, this study was conducted to understand the transmission routes and prevent another AHC outbreaks. METHODS: The authors conducted a questionnaire survey among 1, 730 students from 2 middle schools and 1 technical high school in Gyeongju city. For statistical analysis the chi-square test was used, and chi-square for trend method showing a level of significance less than p< 0.05 was proven to be significant. Variables which were proven to be significant in univariate analysis were analysed by multiple logistic regression. RESULTS: The attack rate was 57.1%. The student groups with rubbing one's own eyes, computer usage, and sharing cellular phone had a significantly higher AHC attack rate (p< 0.05). According to the multiple logistic regression, the odds ratios for male, high school, computer use, sharing cellular phone, and rubbing one's own eyes were significant (p< 0.05). CONCLUSION: The most significant feature of this outbreak was that many students rubbed their own eyes following contact with AHC patients in a deliberate attempt to avoid going to school. Other transmission methods were computer usage and sharing cellular phone. In the future, health and school authorities must plan new strategies for the prevention of AHC.
Summary
A Study on Polymorphism Affecting Excretion of Urinary Methylhippuric Acid due to Xylene Exposure.
Cheong Sik Kim, Sang Baek Koh, Hyeongsu Kim, Sue Kyung Park, Soung Hoon Chang
J Prev Med Public Health. 2004;37(4):321-328.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVES
The purpose of this study was to investigate the effect of genetic polymorphism of cytochrome P450 2E1 (CYP2E1) and aldehyde dehydrogenase 2 (ALDH2) on the xylene metabolism. METHODS: Among 247 workers, 116 were occupationally exposed to xylene and 131 were not. Workers exposed to xylene had different work such as spray, touch-up, mix & assist, and pre-treat. Questionnaire variables were age, sex, use of personal protective equipment, smoking, previous night's drinking and work duration. The urinary methylhippuric acid was measured in the urine collected in the afternoon and corrected by urinary creatinine concentration. The genotypes of CYP2E1 and ALDH2 were investigated by using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) methods with DNA extracted from venous blood. RESULTS: 1. The urinary concentrations of o-, m-, and pmethylhippuric acid and total methylhippuric acid in the exposed group were significantly higher than those in the non-exposed group (p< 0.001). 2. In multiple regression analysis, the urinary methylhippuric acid concentration was significantly influenced by exposure grade (Job-exposure matrixes), smoking, drug use and kind of protective equipment (p< 0.1). 3. Genetic polymorphism of CYP2E1 and ALDH2 did not affect urinary methylhippuric acid level in the exposed group (p> 0.05). CONCLUSIONS: Exposure grade, smoking, drug use and kind of protective equipment affected urinary methylhippuric acid level, whereas genetic polymorphism of CYP2E1 and ALDH2 did not. However, further investigation for the effect of genetic polymorphism on the metabolism of xylene with a larger sample size is needed.
Summary
The Mechanism of Iron Transport after Intratracheal Instillation of Iron in Rats.
Min Kwon, Byung Sun Choi, Eon Sub Park, Nam Hyun Chung, Sungjo Park, Young Lim, Jung Duck Park
J Prev Med Public Health. 2004;37(4):329-336.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVES
Iron (Fe) is an essential element in biological processes; however excessive Fe is harmful to human health. Some air pollutants contain a high level of Fe, and the human lung could therefore be over-exposed to Fe through inhaled air pollutants. This study was performed to investigate the role of metal transporters (divalent metal transporter 1, DMT1, and metal transporter protein 1, MTP1) in the lung under the environments of Fe deficiency in the body and Fe over-exposure in the lung. METHODS: Rats were fed Fe deficient (FeD, 2-6 mg Fe/kg) or Fe supplemented (FeS, 120 mg Fe/kg) diet for 4 weeks, followed by a single intratracheal instillation of ferrous sulfate at low (10 mg/kg) or high (20 mg/kg) dose. Fe concentration was analyzed in the serum, lung and liver, and histopathological findings were observed in the lung at 24 hours after Fe administration. The level of DMT1 and MTP1 expression in the lung was analyzed by RT-PCR. Also, the effect of Fe deficiency in the body was evaluated on the level of Fe concentration and metal transporters compared to FeS-diet fed rats at the end of 4-week FeD or FeS diet. RESULTS: The 4-week FeD diet in rats induced an Fe deficiency anemia with decreased serum total Fe, increased unsaturated Fe binding capacity and hypochromic microcytic red blood cells. The concentration of Fe in the lung and liver was lower in the FeD-diet fed rats than in the FeS-diet fed rats. The level of metal transporters mRNA expression was higher in the FeD-diet fed rats than in the FeS-diet. The concentration of Fe in the lung was increased in a dose-dependent pattern after intratracheal instillation of Fe into the rats, while the level of Fe in the serum and liver was not increased in the low-dose Fe administered rats. Therefore, DMT1 and MTP1 mRNA was highly expressed in both FeD-diet and FeS-diet fed rats, after intratracheal instillation of Fe. CONCLUSIONS: DMT1 and MTP1 mRNA were more highly expressed in FeD-diet fed rats than in FeS-diet fed rats. The over-exposure of Fe intratracheally induced high expression of metal transporters and increased Fe deposition in the lung in both FeD-diet and FeS-diet fed rats, but did not increase the Fe level of the serum and liver in low-dose Fe administered rats. These results suggest that the role of metal transporters in the lung might be different in a part from the duodenum under the environment of over-exposure to Fe.
Summary
Incidence Density of Antibody against Hepatitis C Virus in Seoul and Gyeonggi Area; A Retrospective Cohort Study: Based on Medical Screening Data from a General Hospital.
Seung Ho Ryu, Dong Il Kim, Byung Seong Suh, Woon Sool Kim, Yoo Soo Chang, Sung Ho Beck, Soo Jin Lee, Jaechul Song, Yong Kyu Kim
J Prev Med Public Health. 2004;37(4):337-344.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVES
This study was performed to determine the incidence density and the prevalence of sero-positive hepatitis C from 1999 to 2002 among adults aged 20 and over residing in Seoul and the Gyeonggi province. METHOD: The data for period was obtained from 114, 635 adults, residing in Seoul or the Gyeonggi province, who had undertaken comprehensive health screening tests from Jan 1999 to Dec 2002 in a University hospital in Seoul. Among them, subjects with sero-negative status against hepatitis C were selected (21, 408 in 1999, 28, 830 in 2000) and then followed up until Dec 2002 to determine the incidence of hepatitis C during this period. The serum was tested with the immunoradiometric assay (IRMA) which uses third generation HCV antibody. Age adjusted rates were estimated by direct standardization using a reference population of 2000 aged from 20 to 80 years. RESULTS: The prevalence of anti-HCV from 1999 to 2002 was 2.1 per 1000 persons (95% CI 1.8~2.4). Male showed 1.7 per 1000 persons (95% CI 1.4~2.1), while female showed 2.7 per 1000 persons (95% CI 2.2~3.2). Age?sex adjusted rate showed 2.8 per 1000 persons (95% CI 2.64~2.96), which is lower than the results of some previous study. The prevalence showed a significantly increasing pattern with age both in males and females (p< 0.05). The incidence density of anti-HCV among the population aged 20 and over was 1.1 per 104 person-years at risk (95% CI 0.6~2.4) ; 1.2 (95% CI 0.6~2.7) for males and 0.8 (95% CI 0.6~4.2) for females. Age adjusted incidence density was 2.91 per 104 person-years at risk (95% CI 2.43~3.38) for those aged 20 and over. It showed an increasing pattern with age (p< 0.05), especially for those age over 50 years. CONCLUSION: The study subjects for this study were supposedly healthier than the general population so the prevalence and incidence for the general population are thought to be higher than the results of the present study.
Summary
Proportion of Death Certificates Issued by Physicians and Associated Factors in Korea, 1990-2002.
Min Woo Jo, Young Ho Khang, Sungcheol Yun, Jin Yong Lee, Moo Song Lee, Sang Il Lee
J Prev Med Public Health. 2004;37(4):345-352.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVES
Previous studies showed that death certification by physicians was an important predictor to improve the quality of death certificate data in South Korea. This study was conducted to examine the proportion of death certificates issued by physicians and associated factors in South Korea from 1990 to 2002. METHODS: Data from 3, 110, 883 death certificates issued between 1990 and 2002, available to the public from the National Statistical Office of Korea, were used to calculate the proportion of death certificates issued by physicians and to examine associated factors with logistic regression analysis. RESULTS: The overall proportion of death certificates issued by physicians increased from 44.6% in 1990 to 77.6% in 2002 (mean: 63.5%). However, the proportion was greatly influenced by the deceased's age. In 2002, more than 90% of the deceased aged 51 or less were certified by physicians. A higher proportion was found among deceased who had tertiary education (college or higher) living in more developed urban areas. CONCLUSION: The information regarding the cause of death for younger, well-educated deceased in urban areas of South Korea may show a higher level of accuracy. Epidemiologic research using information on causes of death may well benefit from the continually increasing proportion of death certificates issued by physicians in the future in South Korea.
Summary
Cost-Utility Analysis of the Cochlear Implant.
Hoo Yeon Lee, Hee Nam Kim, Han Joong Kim, Jae Young Choi, Eun Cheol Park
J Prev Med Public Health. 2004;37(4):353-358.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVE
To determine the quality of life and cost consequences for deaf adults who received a cochlear implant. METHODS: The data from 11 patients, post-lingual deaf adults who received cochlear implants from 1990 to 2002, underwent cost-utility analysis. The average age of the participants was 49.6 years. The main outcomes were direct cost per quality-adjusted life-year (QALY) using the visual analog scale (VAS), health utility index (HUI), EuroQol (EQ-5D), and quality well-being (QWB), with costs and utilities being discounted 3% annually. RESULTS: Recipients had an average of 5.6 years of implant use. Mean VAS scores increased by 0.33, from 0.27 before implantation to 0.60 at survey. HUI scores increased by 0.36, from 0.29 to 0.65, EQ-5D scores increased by 0.26, from 0.52 to 0.78, and QWB scores increased by 0.16, from 0.45 to 0.61. Discounted direct costs were $22, 320, yielding $19, 223/QALY using VAS, $17, 387/QALY using HUI, $24, 604/QALY using EQ-5D, and $40, 474/QALY using QWB. Cost-utility ratios using VAS, HUI, and EQ-5D were all below $25, 000 per QALY, except using QWB. CONCLUSION: Cochlear implants in post-lingual deaf adult have a positive effect on quality of life at reasonable direct costs and appear to produce a net saving to society.
Summary
Abdominal Obesity in Relation to the Incidence of Type 2 Diabetes Mellitus and Impaired Fasting Glucose among some Korean Adults: A Retrospective Cohort Study.
Seung Ho Ryu, Sung Ho Beck, Yoo Soo Chang, Dong Il Kim, Byung Seong Suh, Woon Sool Kim, Ki Chul Sung
J Prev Med Public Health. 2004;37(4):359-365.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVES
This study was performed to determine whether an increase in abdominal obesity is an independent risk factor for impaired fasting glucose and type 2 DM. METHODS: Among 24, 212 adults over 30 years who undertook comprehensive medical screening examinations from Jan to Dec 1999, in a university hospital in Seoul, a total of 11, 183 subjects were selected who had no DM at baseline and who were followed up more than once by Dec 2002. The average follow up period was 2.4 (+/-0.5) years. DM was defined as having a fasting glucose level > or = 126mg/dl, and impaired fasting glucose as showing a fasting glucose level between 110 and 125 mg/dl. Body weight, height and waist circumference (WC) were simultaneously measured with blood sampling. The relative risks (RRs) for DM and impaired fasting glucose by WC were calculated using Cox proportional hazard model. Ageadjusted rates were estimated by direct standardization using a reference population of 2000 from 30 to 80 years. RESULTS: The average age of the subjects was 41.7 (+/- 7.0) years; males 41.2 (+/-6.5) and females 45.6 (+/-9.2). RRs for type 2 DM by WC with the reference group of WC < 80cm were as follows: 2.66 (95%, CI 0.55~12.8) for WC of 80~89cm in men, 5.92 (95%, CI 1.08~32.3) for WC > or = 90 cm in men, and 2.64 (95%, CI 0.23~29.8) for WC of 80~89cm in females. RRs for impaired fasting glucose by WC were 3.03 (95%, CI 2.18~4.22) for WC 80~89cm in men, 6.10 (95%, CI 4.25~8.75) for WC > or = 90cm in men, and 1.56 (95%, CI 0.43~5.67) for WC 80~89cm in women, and 8.08 (95%, CI 2.22~29.4) for WC > or = 90cm in females. These results remained significant after adjustment for age, BMI and fasting glucose concentrations at baseline in both sexes. Annual increment of more than 1 cm in WC was associated with the development of DM and impaired fasting glucose independently of age, sex, BMI, or presence of abdominal obesity. CONCLUSION: In Korean adults, abdominal obesity increased the risk for the development of type 2 diabetes and impaired fasting glucose. This result supports many other prospective studies suggesting abdominal obesity as a risk factor for type 2 diabetes.
Summary
Statistical Algorithm in Genetic Linkage Based on Haplotypes.
Jinheum Kim, Dae Ryong Kang, Yun Kyung Lee, Sun Mi Shin, Il Suh, Chung Mo Nam
J Prev Med Public Health. 2004;37(4):366-372.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVES
This study was conducted to propose a new transmission/disequilibrium test (TDT) to test the linkage between genetic markers and diseasesusceptibility genes based on haplotypes. Simulation studies were performed to compare the proposed method with that of Zhao et al. in terms of type I error probability and powers. METHODS: We estimated the haplotype frequencies using the expectation-maximization (EM) algorithm with parents' genotypes taken from a trio dataset, and then constructed a two-way contingency table containing estimated frequencies to all possible pairs of parents' haplotypes. We proposed a score test based on differences between column marginals and their corresponding row marginals. The test also involved a covariance structure of marginal differences and their variances. In simulation, we considered a coalescent model with three genetic markers of biallele to investigate the performance of the proposed test under six different configurations. RESULTS: The haplotype-based TDT statistics, our test and Zhao et al.'s test satisfied a type I error probability, but the TDT test based on single locus showed a conservative trend. As expected, the tests based on haplotypes also had better powers than those based on single locus. Our test and that of Zhao et al. were comparable in powers. CONCLUSION: We proposed a TDT statistic based on haplotypes and showed through simulations that our test was more powerful than the single locus-based test. We will extend our method to multiplex data with affected and/or unaffected sibling (s) or simplex data having only one parent's genotype.
Summary
DNA Damage of Lymphocytes in Volunteers after 4 hours Use of Mobile Phone.
Seonmi Ji, Eunha Oh, Donggeun Sul, Jae Wook Choi, Heechan Park, Eunil Lee
J Prev Med Public Health. 2004;37(4):373-380.   Published online November 30, 2004
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AbstractAbstract PDF
OBJECTIVES
There has been gradually increasing concern about the adverse health effects of electromagnetic radiation originating from cell phones which are widely used in modern life. Cell phone radiation may affect human health by increasing free radicals of human blood cells. This study has been designed to identify DNA damage of blood cells by electromagnetic radiation caused by cell phone use. METHODS: This study investigated the health effect of acute exposure to commercially available cell phones on certain parameters such as an indicator of DNA damage for 14 healthy adult volunteers. Each volunteer during the experiment talked over the cell phone with the keypad facing the right side of the face for 4 hours. The single cell gel electrophoresis assay (Comet assay), which is very sensitive in detecting the presence of DNA strand-breaks and alkali-labile damage in individual cells, was used to assess peripheral blood cells (T-cells, B-cells, granulocytes) from volunteers before and after exposure to cell phone radiation. The parameters of Comet assay measured were Olive Tail Moment and Tail DNA %. RESULTS: The Olive Tail Moment of B-cells and granulocytes and Tail DNA % of B-cells and granulocytes were increased by a statistically significant extent after 4- hour use of a cell phone compared with controls. CONCLUSION: It is concluded that cell phone radiation caused the DNA damage during the 4 hours of experimental condition. Nonetheless, this study suggested that cell phone use may increase DNA damage by electromagnetic radiation and other contributing factors.
Summary
Clinical Trial
Analysis of Repeated Measured VAS in a Clinical Trial for Evaluating a New NSAID with GEE Method.
Hoi Jeong Lim, Yooni Kim, Young Bok Jung, Sang Cheol Seong, Jin Hwan Ahn, Kwon Jae Roh, Jung Man Kim, Byung Joo Park
J Prev Med Public Health. 2004;37(4):381-389.   Published online November 30, 2014
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AbstractAbstract PDF
OBJECTIVE
: To compare the efficacy between SKI306X and Diclofenac by using generalized estimating equations (GEE) methodology in the analysis of correlated bivariate binary outcome data in Osteoarthritis (OA) diseases. METHODS: A randomized, double-blind, active comparator controlled, non-inferiority clinical trial was conducted at 5 institutions in Korea with the random assignment of 248 patients aged 35 to 75 years old with OA of the knee and clinical evidence of OA. Patients were enrolled in this study if they had at least moderate pain in the affected knee joint and a score larger than 35mm as assessed by VAS (Visual Analog Scale). The main exposure variable was treatment (SKI 306X vs. Diclofenac) and other covariates were age, sex, BMI, baseline VAS, center, operation history (Yes/No), NSAIDS (Y/N), acupuncture (Y/N), herbal medicine (Y/N), past history of musculoskeletal disease (Y/N), and previous therapy related with OA (Y/N). The main study outcome was the change of VAS pain scores from baseline to the 2nd and 4th weeks after treatment. Pain scores were obtained as baseline, 2nd and 4th weeks after treatment. We applied GEE approach with empirical covariance matrix and independent (or exchangeable) working correlation matrix to evaluate the relation of several risk factors to the change of VAS pain scores with correlated binary bivariate outcomes. RESULTS: While baseline VAS, age, and acupuncture variables had protective effects for reducing the OA pain, its treatment (Joins/Diclofenac) was not statistically significant through GEE methodology (ITT: aOR=1.37, 95% CI= (0.8200, 2.26), PP: aOR=1.47, 95% CI= (0.73, 2.95) ). The goodness-off it statistic for GEE (6.55, p=0.68) was computed to assess the adequacy of the fitted final model. CONCLUSIONS: Both ANCOVA and GEE methods yielded non statistical significance in the evaluation of non-inferiority of the efficacy between SKI306X and Diclofenac. While VAS outcome for each visit was applied in GEE, only VAS outcome for the fourth visit was applied in ANCOVA. So the GEE methodology is more accurate for the analysis of correlated outcomes.
Summary

JPMPH : Journal of Preventive Medicine and Public Health