1.Evaluation of imaging performance of major image guidance systems
Chan MF* ; Yang J ; Song Y ; Burman C ; Chan P ; Li S
Biomedical Imaging and Intervention Journal 2011;7(2):1-7
Purpose: The imaging characteristics of two popular kV cone-beam CT (CBCT) and two MVCT systems utilised in
image-guided radiation therapy (IGRT) were evaluated.
Materials and methods: The study was performed on Varian Clinac iX, Elekta Synergy S, Siemens Oncor, and
Tomotherapy. A CT phantom (Catphan-504, Phantom Laboratory, Salem, NY) was scanned for measurements of image
quality including image noise, uniformity, density accuracy, spatial resolution, contrast linearity, and contrast resolution.
The measurement results were analysed using in-house image analysis software. Reproducibility, position correction,
and geometric accuracy were also evaluated with markers in a smaller alignment phantom. The performance evaluation
compared volumetric image properties from these four systems with those from a conventional diagnostic CT (CCT).
Results: It was shown that the linearity of the two kV CBCT was fairly consistent with CCT. The Elekta CBCT
with half-circle 27-cm FOV had higher CT numbers than the other three systems. The image noises of the Elekta kV
CBCT, Siemens MV CBCT, and Tomotherapy fan-beam CT (FBCT) are about 2-4 times higher than that of the Varian
CBCT. The spatial resolutions of two kV CBCTs and two MV CBCTs were 8-11 lp/cm and 3-5 lp/cm, respectively.
Conclusion: Elekta CBCT provided a faster image reconstruction and low dose per scan for half-circle scanning.
Varian CBCT had relatively lower image noise. Tomotherapy FBCT had the best uniformity.
2.Validation of the Paediatric Hearing Impairment Caregiver Experience (PHICE) Questionnaire.
Lynne H Y LIM ; Ling XIANG ; Naomi L Y WONG ; Kevin C P YUEN ; Ruijie LI
Annals of the Academy of Medicine, Singapore 2014;43(7):362-370
<p>INTRODUCTIONThe paediatric hearing impairment caregiver experience (PHICE) questionnaire is a 68-item instrument that assesses the stress experienced by caregivers of children with hearing impairment (HI). While the questionnaire has been validated in the United States, it may need to be modified for use in the Singapore context due to the differing healthcare system, costing and culture related to caregiving for children with HI. This study aims to modify and validate the PHICE questionnaire to increase its relevance and ease of use in Singapore.p><p>MATERIALS AND METHODSThe original PHICE questionnaire was filled out by 127 caregivers of HI children managed at the otolaryngology clinic of the National University Hospital (NUH). An expert panel was convened to assess the questionnaire for its suitability for use in Singapore. Exploratory factor analysis was conducted to evaluate the underlying factor structure of the original PHICE questionnaire. Items with high cross-loadings were removed and a new factor structure was adopted which was further analysed using confirmatory factor analysis (CFA). Cronbach's alpha (α) was computed to determine the internal consistency of the new subscales.p><p>RESULTSItems that are less relevant in Singapore and those with high cross-loadings were removed. A 5-factor structure with only 42 items remaining and corresponding to the factors: " Policy", "Healthcare", "Education", "Support" and "Adaptation" was adopted. CFA suggests a good model fit for the modified questionnaire, improved from the 8-factor structure of the original PHICE. Cronbach's α were high (>0.7) for each new subscale.p><p>CONCLUSIONThe original PHICE questionnaire has been shortened and reorganised in terms of the subscales composition. The resulting instrument is structurally valid and internally consistent. It is a simple and useful tool for identifying factors related to caregiving that can negatively impact rehabilitation outcomes for children with HI in Singapore. Removal of some sign language items makes this modified version less useful for caregivers, places or countries where sign language is the main focus of rehabilitation for children with HI.p>
Adolescent
;
Caregivers
;
Child
;
Child, Preschool
;
Female
;
Hearing Loss
;
therapy
;
Humans
;
Infant
;
Infant, Newborn
;
Male
;
Singapore
;
Surveys and Questionnaires
3.Transmission cluster and network of HIV-1 CRF01_AE strain in China, 1996-2014.
X L WANG ; L JIA ; H P LI ; Y J LIU ; J W HAN ; T Y LI ; J Y LI ; L LI
Chinese Journal of Epidemiology 2019;40(1):84-88
Objective: To understand the transmission patterns and risk factors of HIV-1 strain CRF01_AE subtypes in China, and to provide guidance for the implementation of precise intervention. Methods: A total of 2 094 CRF01_AE pol sequences were collected in 19 provinces in China between 1996 and 2014. Phylogenetic tree was constructed by PhyML 3.0 software to select the transmission clusters. Transmission network was constructed by Cytoscape 3.6.0, which was further used for exploring of the major risk factors. Results: Of the 2 094 sequences, 12.18% (255/2 094) were in clusters. A total of 82 transmission clusters were identified. The numbers of clusters and contained sequences in intra-provincial transmission (61, 173) were significantly more than those in inter-provincial transmission (21, 82). The ratio of transmission clustering in MSM increased over time from 2.41% (2/83) during 1996-2008 to 23.61% (72/305) during 2013-2014, showing a significant upward trend (χ(2)=27.800, df=1, P=0.000). The proportion of MSM with inter-provincial transmission clusters were higher than those with intra-provincial transmission clusters, which increased from 0.67% (2/297) during 1996-2008 to 6.36%(30/472) during 2013-2014, showing a significant upward trend (χ(2)=20.276, df=1, P=0.000). The transmission rate in homosexuals of the inter-transmission clusters (86.59%, 71/82) was higher than that of intra-provincial transmission clusters (56.65%, 98/173), and the difference was statistically significant (χ(2)=22.792, P=0.000). The proportion of inter-provincial transmission clusters with more than 2 transmission routes (33.33%, 7/21) was higher than that of intra-provincial clusters (13.11%, 8/61), and the difference was statistically significant (χ(2)=4.273, P=0.039). Results from the transmission network analysis indicated that the proportion of high risk population (degree≥4) with inter-provincial transmission clusters (51.22%, 42/82) was significantly higher than that with intra-provincial transmission clusters (26.59%, 46/173), and the difference was statistically significant (χ(2)=14.932, P=0.000). Inter-provincial clusters were mainly detected in and and MSM. Conclusions: Complex transmission networks were found for HIV-1 CRF01_AE strains in the mainland of China. Inter-provincial transmission clusters increased rapidly, MSM played an important role in the wide spread of the strain. More researches in transmission networks are needed to guide the precision intervention.
China/epidemiology*
;
HIV Infections/virology*
;
HIV-1/isolation & purification*
;
Homosexuality, Male/statistics & numerical data*
;
Humans
;
Male
;
Phylogeny
4.A Meta-analysis on the relations between short-term exposure to PM(2.5) and both mortality and related emergency visits in China.
M LI ; Y WU ; Y H TIAN ; G Y CAO ; S S YAO ; P AI ; Z HUANG ; C HUANG ; X W WANG ; Y Y CAO ; X XIANG ; J JUAN ; Y H HU
Chinese Journal of Epidemiology 2018;39(10):1394-1401
Objective: To carry out a quantitative estimate that related to the effects of short-term exposure to PM(2.5) on all-cause mortality and emergency visits in China by using the systematic review and Meta-analysis. Methods: We selected all the studies published before March 2018 from China National Knowledge Infrastructure, Wanfang database, PubMed and EMBASE and data on relative risk (RR), excess risk (ER) and their 95%CIs: appeared in these papers were extracted. According to the differences in the size or direction (heterogeneity) of the results, we computed summary estimates of the effect values using a random-effect or fixed effect model. We also conducted the subgroup analysis and Meta-analysis to have assessed the selected studies for the evidence of study bias. Results: A total of 33 original studies, indexed in databases, were identified. Among those studies, 39 sets of data on mortality and 4 sets of data on emergency were valid to show that within the daily concentration range from 47.7 to 176.7 μg/m(3), for 10 μg/m(3) increases in PM(2.5) concentrations, it would increase the daily numbers of deaths by 0.49% (95%CI: 0.39%-0.59%) and 0.30% (95%CI: 0.10%-0.51%) for all-cause deaths and all-cause emergency-room visits, respectively. For subgroup analysis, the combined effect of PM(2.5) in causing short-term all-cause deaths in the northern areas (ER=0.42%, 95%CI: 0.30%-0.54%) seemed lower than that in the southern areas (ER=0.63%, 95%CI: 0.44%-0.82%). The combined effect of PM(2.5) concentration below 75 μg/m(3) (ER=0.50%, 95%CI: 0.37%-0.62%) was higher than that of PM(2.5) concentration ≥75 μg/m(3) (ER=0.39%, 95%CI: 0.26%-0.52%). Conclusion: Within the concentration range from 47.7 to 176.7 μg/m(3), short-term exposure to current level of PM(2.5) might increase both the all-cause daily mortality and daily emergency visits in China.
Air Pollutants
;
Air Pollution/statistics & numerical data*
;
China
;
Databases, Factual
;
Emergency Service, Hospital/statistics & numerical data*
;
Environmental Exposure/statistics & numerical data*
;
Female
;
Humans
;
Male
;
Particulate Matter/toxicity*
;
Time Factors
5.Disease burden of animal injury in China, 1990-2016.
P P YE ; Y JIN ; C R JI ; Y L ER ; L L DUAN ; Z X LI
Chinese Journal of Epidemiology 2019;40(1):52-58
Objective: To analyze the disease burden of animal injury in China between 1990 and 2016. Methods: Data obtained from the Global Burden of Disease 2016 were used to analyze the age and gender specific disease burden of animal injury in China, using the incidence and disability adjusted of life years (DALYs) rate. Relative and annual changes were evaluated. Results: In 2016, the age-standardized incidence and DALYs rate of animal injury in China showed as 245.05 per 100 000 people and 12.73 per 100 000. The age-standardized incidence of non-venomous animal injury was significantly higher than that of venomous animal injury, but the differences in age-standardized incidence and DALYs rate between venomous animal injury and non-venomous animal injury were not significant. Between 1990 and 2016, there was a significantly decreasing trend in the age-standardized incidence and DALYs rate of animal injury, and obvious decline could be seen in the incidence of non-venomous animal injury, compared with venomous animal injury. The incidence and DALYs rate of animal injury declined in both males and females and in different age groups. The obvious decline of incidence and DALYs rate could be found in children aged 5-14 years and aged <5 years. Conclusions: Between 1990 and 2016, there was a significant alleviation of the disease burden of animal injury in China. Young children were most prone to animal injury, resulting in serious disability and death, indicating more attention should be paid to this population at high risk and in animal injury prevention and control programs.
Adolescent
;
Child
;
Child, Preschool
;
China/epidemiology*
;
Cost of Illness
;
Disabled Persons/statistics & numerical data*
;
Female
;
Global Burden of Disease
;
Humans
;
Incidence
;
Male
;
Quality-Adjusted Life Years
;
Wounds and Injuries/epidemiology*
6.Stratified sampling survey of major human parasitic diseases in Henan province.
B L XU ; H W ZHANG ; Y DENG ; Z L CHEN ; W Q CHEN ; D L LU ; Y L ZHANG ; Y L ZHAO ; X M LIN ; Q HUANG ; C Y YANG ; Y LIU ; R M ZHOU ; P LI ; J S CHEN ; L J HE ; D QIAN
Chinese Journal of Epidemiology 2018;39(3):322-328
Objective: To understand the prevalence of major human parasitic diseases and related factors in Henan province. Methods: This stratified sampling survey was carried out according to the requirement of national survey protocol of major human parasitic diseases, 2014-2015. The prevalence of soil-transmitted helminths infection, taeniasis and intestinal protozoiasis were surveyed in 104 sites selected from 35 counties (districts) and the prevalence of clonorchiasis was surveyed in 62 sites selected from 37 townships. In each survey spot, 250 persons were surveyed. A total of 26 866 persons and 15 893 persons were surveyed. Modified Kato-Katz thick smear was used to detect the eggs of intestinal helminthes. Tube fecal culture was used to identify the species of hookworm. The Enterobius eggs were detected in children aged 3 to 6 years by using adhesive tape. The cyst and trophozoite of intestinal protozoa were examined with physiological saline direct smear method and iodine stain method. Results: The overall infestation rate of intestinal parasites was2.02% in Henan, and the worm infection rate was higher than protozoa infection rate. Fourteen kinds of intestinal parasites were found, including nematode (5 species), trematode (2 species), and protozoan (7 species). The infection rate of Enterobius vermicularis was highest, and Qinba Mountain ecological area had the highest infestation rate of intestinal parasites in 4 ecological areas of Henan. There was no significant difference in intestinal parasite infection rate between males and females (χ(2)=3.630, P=0.057), and the differences in intestinal parasite infection rate among different age groups had significance (χ(2)=124.783, P=0.000 1). The infection rate reached the peak in age group ≤9 years and the major parasite was Enterobius vermicularis. Furthermore the overall human infection rate of parasite showed a downward trend with the increase of educational level of the people (χ(2)=70.969, P=0.000 1), the differences had significance (χ(2)=120.118, P=0.000 1). For different populations, the infection rate of intestinal parasites was highest among preschool children. The infection of intestinal helminth was mainly mild, only 2 severe cases were detected. The infection rate of Clonorchis sinensis in urban residents was only 0.006%. Logistic regression analysis showed that being preschool children (χ(2)=15.765, P=0.000 1) and drinking well water (χ(2)=45.589, P=0.000 1) were the risk factors for intestinal parasite infection, and annual income per capita of farmers was the protective factor against intestinal parasite infection. The infection rates of protozoa and intestinal parasites decreased sharply compared with the results of previous two surveys, and the rate of intestinal helminth infection also dropped sharply compared with the second survey. The numbers of protozoa, helminth and intestinal parasites detected in this survey were all less than the numbers found in the previous two surveys. Conclusions: Compared the results of three surveys in Henan, the infection rate of protozoa and intestinal parasites showed a downward trend. The prevention and treatment of Enterobius vermicularis infection in children should be the key point of parasitic disease control in the future.
Animals
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Child
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Child, Preschool
;
Clonorchiasis/epidemiology*
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Farmers
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Feces/parasitology*
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Female
;
Helminthiasis/epidemiology*
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Helminths
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Humans
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Intestinal Diseases, Parasitic/parasitology*
;
Male
;
Prevalence
;
Protective Factors
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Risk Factors
;
Rural Population
;
Soil Microbiology
;
Surveys and Questionnaires
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Taeniasis/epidemiology*
;
Trematode Infections/parasitology*
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Urban Population
;
Water Wells
7.Study on the effectiveness of implementation: the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases.
J ZHANG ; R R JIN ; J J LI ; J L LI ; X W SU ; G J DENG ; S MA ; J ZHAO ; Y P WANG ; F BIAN ; Y M QU ; Z Z SHEN ; Y JIANG ; Y L LIU
Chinese Journal of Epidemiology 2018;39(4):394-400
Objective: To assess the implementation and impact of programs carried out by the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases. Methods: Both sociological and epidemiological methods were used to collect qualitative and quantitative data in November and December, 2016 in order to conduct on process and outcome evaluation of the above mentioned objective. In the meantime, case study was also conducted. Results: All the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases were found well implemented across the country, with health education and health promotion, surveillance and safeguard measures in particular. A government-led and inter-sector coordination and communication mechanism had been well established, with more than 16 non-health departments actively involved. 28.7% of the residents living in the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases were aware of the key messages related to chronic diseases. Among the residents, 72.1% of them consumed vegetables and 53.6% consumed fruits daily, with another 86.9% walked at least 10 minutes per day. Over 70% of the patients with hypertension or diabetes reported that they were taken care of by the Community Health Centers, and above 50% of them were under standardized management. Residents, living in the National Demonstration Areas under higher ranking of implementation scores, were more likely to be aware of relevant knowledge on chronic disease control and prevention (OR=6.591, 95%CI: 5.188-8.373), salt reduction (OR=1.352, 95%CI: 1.151-1.589), oil reduction (OR=1.477, 95%CI: 1.249-1.746) and recommendation on physical activities (OR=1.975, 95%CI: 1.623- 2.403). Conclusion: The implementation of programs carried out by the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases had served a local platform for the control and prevention of non-communicable diseases, and thus become an important 'carrier' for chronic disease prevention and control programs in China.
China/epidemiology*
;
Chronic Disease/epidemiology*
;
Delivery of Health Care
;
Health Promotion/organization & administration*
;
Humans
;
National Health Programs
;
Noncommunicable Diseases/prevention & control*
;
Outcome Assessment, Health Care
;
Population Surveillance
;
Preventive Health Services/organization & administration*
;
Program Evaluation
;
Public Health
8.Antibiotic resistance in gram-negative bacilli: a Singapore perspective.
Thean Yen TAN ; Li Yang HSU ; Tse Hsien KOH ; Lily S Y NG ; Nancy W S TEE ; Prabha KRISHNAN ; Raymond T P LIN ; Roland JUREEN
Annals of the Academy of Medicine, Singapore 2008;37(10):819-825
<p>INTRODUCTIONAntibiotic resistance in gram-negative bacilli is an area of increasing importance. This prospective study was performed to survey antibiotic resistance in Escherichia coli (E. coli), Klebsiella spp., Pseudomonas aeruginosa and Acinetobacter spp. over a 1-year period.p><p>MATERIALS AND METHODSNon-duplicate isolates of E. coli, Klebsiella spp., P. aeruginosa and Acinetobacter spp. were collected from participating Singapore hospitals during defined collection periods in 2006 and 2007. Confirmatory identification and antibiotic susceptibility testing were performed at Changi General Hospital. Minimum inhibitory concentrations (MIC) to a defined panel of antibiotics were determined using microbroth dilution methods. The presence of extended-spectrum beta lactamases and AmpC beta-lactamases in Enterobacteriaceae was determined by phenotypic methods, and susceptibility results were defined using current breakpoints from the Clinical Laboratory Standards Institute (CLSI).p><p>RESULTSSeven hundred and forty-six gram-negative bacilli were received for testing. Resistance to extended-spectrum cephalosporins was present in a third of Enterobacteriaceae isolates, and extended-spectrum beta-lactamases (ESBL) carriage was present in 19.6% and 30.1% of E. coli and Klebsiella pneumoniae, respectively. AmpC enzymes were also detected in 8.5% and 5.6% of E. coli and K. pneumoniae isolates respectively. All Enterobacteriaceae were susceptible to imipenem and meropenem. The most active antibiotics against P. aeruginosa were amikacin, meropenem and piperacillin-tazobactam. A third of P. aeruginosa showed reduced susceptibility to polymyxin B. Carbapenem resistance was significantly higher in Acinetobacter baumannii (70.5%) than in other Acinetobacter species (25.0%). The most active antibiotic against A. baumannii was polymyxin B.p><p>CONCLUSIONAntibiotic resistance is prevalent in gram-negative bacilli isolated from Singapore hospitals. The MIC testing surveillance programme complemented susceptibility data from wider laboratory-based surveillance, and has revealed emerging mechanisms of antibiotic resistance.p>
Acinetobacter Infections
;
drug therapy
;
Acinetobacter baumannii
;
drug effects
;
isolation & purification
;
Anti-Bacterial Agents
;
pharmacology
;
therapeutic use
;
Bacterial Proteins
;
Drug Resistance, Bacterial
;
Escherichia coli
;
drug effects
;
enzymology
;
Hospitals
;
Humans
;
Klebsiella Infections
;
drug therapy
;
Klebsiella pneumoniae
;
drug effects
;
enzymology
;
Microbial Sensitivity Tests
;
Prospective Studies
;
Pseudomonas aeruginosa
;
drug effects
;
isolation & purification
;
Singapore
;
beta-Lactamases
9.Polymorphisms of four STRs and their associations with IDDM in Chinese Han population.
Z A ; S ZHANG ; C XIAO ; W LI ; Y HOU ; J ZHU ; J WANG
Chinese Journal of Medical Genetics 2000;17(4):248-251
<p>OBJECTIVETo obtain the polymorphic data of short tandem repeat(STR) loci of D15S657, D11S1369, D6S2420 and D6S503 in Chinese Han population and to study the association of these four STR loci with insulin-dependent diabetes mellitus(IDDM).p><p>METHODSThe polymorphisms of the four STRs were studied by polymerase chain reaction-polyacrylamide gel electrophoresis(PCR-PAGE) followed by direct sequencing of PCR products in 105 normal Chinese Hans and 48 patients with IDDM.p><p>RESULTSSeven alleles at D15S657 locus, 5 alleles at D11S1369 locus, 7 alleles at D6S2420 locus and 4 alleles at D6S503 locus were found. No deviation from Hardy-Weinberg equilibrium was observed. The heterozygosities of these loci were 0. 7524, 0.6000, 0.6286, 0.6571 and the polymorphic information contents(PIC) 0.7616, 0.4430, 0.5345 and 0.5932, respectively. The allele frequencies of allele A(5) at D15S657 locus, allele A(5) at D11S1369 locus and allele A(4) at D6S2420 locus were increased significantly in patients with IDDM, compared to those in the control group.p><p>CONCLUSIONThe four STRs, used as genetic markers, were suitable for case-control study, forensic medicine identification and population genetic study. There is an association between the polymorphisms of D15S657, D11S1369, D6S2420 and IDDM.p>
Adult
;
Aged
;
China
;
ethnology
;
Diabetes Mellitus, Type 1
;
genetics
;
Female
;
Humans
;
Male
;
Middle Aged
;
Polymorphism, Genetic
;
Tandem Repeat Sequences
10.Situation and reasons for missed follow-up services among newly reported HIV/AIDS cases transmitted by homosexual behavior in China, 2008-2015.
J XU ; J HAN ; H L TANG ; J LI ; C P ZANG ; Y R MAO
Chinese Journal of Epidemiology 2018;39(4):495-499
Objective: To determine the prevalence and relative factors on those who missed the follow-up service among newly reported HIV/AIDS cases that were infected by homosexual behavior. Methods: Data were extracted from both HIV/AIDS case-reporting and follow-up cards on HIV/AIDS in the Comprehensive Response Information Management System, between December 2008 and December 2015. Data was analyzed, using the generalized estimating equations (GEE) to explore the relative factors of influence. Results: Among the newly reported HIV infection among MSM, the proportion of those who missed the follow-up services was 5.06% (6 037/119 358), and decreased dramatically, from 37.57% (1 261/3 356) to 0.84% (267/31 935) (trend χ(2)=103.43, P<0.01). In MSM population, the younger than 20-year olds (OR=1.30, 95%CI: 1.11-1.52), 20-year olds (OR=1.52, 95%CI: 1.36-1.69), 30-year olds (OR=1.22, 95%CI: 1.12-1.34), 40-year olds (OR=1.10, 95%CI: 1.01-1.20) were receiving less follow-up services than those 50-year olds. Those who had received either junior (OR=1.52, 95%CI: 1.37-1.69) or senior high school education (OR=1.35, 95%CI: 1.23-1.49) were receiving less follow-up service than those who were more educated. MSM with the following characteristics as unspecified occupation (OR=2.06, 95%CI: 1.49-2.87),unemployed (OR=1.54, 95%CI: 1.30-1.83), working in commercial service (OR=1.31, 95%CI: 1.15-1.49) or being student (OR=1.34, 95%CI: 1.18-1.52) were more difficult to be traced or followed than the cadres. Cases being identified on site (OR=2.99, 95%CI: 2.26-3.95) or under special investigation (OR=1.43, 95%CI: 1.29-1.59) had received less follow-up service than those being identified through voluntary counsel testing service. Floating population (OR=1.46, 95%CI: 1.28-1.66) were getting less follow-up service than local residents. Conclusions: The prevalence of those who had missed the follow-up services in the newly discovered MSM HIV cases declined dramatically. Among the MSM HIV cases, those having the following characteristics as: younger than 50-year old, with less school education, with unspecified occupation or unemployment, working in commercial service, being student, having history of incarceration, recruited from special investigation, and floating population were prone to miss the follow-up program, suggesting that the follow-up service should be targeting on these patients.
Acquired Immunodeficiency Syndrome
;
Adolescent
;
Adult
;
China
;
Follow-Up Studies
;
HIV Infections/transmission*
;
Homosexuality, Male/statistics & numerical data*
;
Humans
;
Infections
;
Lost to Follow-Up
;
Male
;
Middle Aged
;
Patient Compliance
;
Prevalence
;
Sexual Behavior/ethnology*
;
Young Adult