Economic evaluation of hepatitis A vaccines by income level of the country: A systematic review

Background & objectives: Although several reviews of economic evaluation (EE) studies on hepatitis A virus (HAV) vaccine exist, there remains a need to corroborate such data from time to time. This study aimed to systematically review the literature for reports on EE of HAV vaccination by type of population, characteristics of intervention and income level of the country. Methods: PubMed and Scopus were searched to identify relevant studies from inception up to May 2021 using topic-specific key words in various combinaiton. Full EE studies comparing HAV vaccination to no vaccine or immunoglobulin were included. The risk of bias was assessed by using the ECOBIAS checklist. Results: Among the 1984 identified studies, 43 were found eligible. Of these, 27 were from high-income countries (HICs), 15 from middle-income countries (MICs), and one from low income country. Majority of the studies used Markov model and/or decision tree (n=26). Eight studies used a dynamic model. The discount rate, perspective and time horizon varied across the studies. Universal HAV vaccination without screening was cost-effective among children (14/16, 87.5%) and adolescents (1/5, 20%) but not in adults (0/4, 0%). Analysis by the level of income found that universal HAV vaccination among children without screening was cost-effective in 81.8 per cent of the studies conducted in MICs (9/11) as compared to 66.7 per cent in HICs (4/6). About one-third of the studies conducted among children found that screening and HAV vaccination were cost-effective compared to no vaccination. Interpretation & conclusions: The finding of this review suggest that universal vaccination of children without screening was likely to be cost-effective, especially in MICs. Nevertheless, it should be noted that the methodology varied across studies. Several aspects should also be considered in transferring the EE results across jurisdictions.

Diagnostic Scores for Appendicitis: A Systematic Review of Scores’ Performance.

Aims: Several scoring systems have been developed for diagnosis of appendicitis. This study aims to systematically explore how those scores were derived and validated, and to compare their performance. Study Design: Systematic review. Place and Duration of Study: We searched Medline from 1949 and EMBASE from 1974 to March 2012 to identify relevant articles published in English. Methodology: Information about model development and performance was extracted. The “risk of bias” assessment tool was developed based on a critical appraisal guide for clinical prediction rules. Calibration (O/E ratio) and discrimination (C-statistic) coefficients were estimated. A meta-analysis was applied to pool calibration coefficients and Cstatistics. Results: Forty-four out of 468 studies were eligible. Of these, 14 developed or modified diagnostic scoring systems and 30 validated existing models. Four scores had been most frequently validated, i.e., Alvarado, modified Alvarado, Fenyo, and Eskelinen. Among them, only the Eskelinen model was derived based on a multivariate regression whereas the rest used univariate or non-statistical methodology. All studies reported very good but imprecise calibration. For discrimination, the pooled C-statistics for these corresponding scores were 0.77, 0.86, 0.81, and 0.84 respectively. In the external validation, the discriminative performance decreased about 25.3% and 10.1% for the Alvarado and Fenyo scores respectively. Conclusion: The research methods for scoring systems of appendicitis were inconsistent. More efficient scoring systems which have been internally and externally validated are required.

Possible protective effects of the Glu27 allele of ß2-Adrenergic receptor polymorphism in Thai asthmatic patients.

The genetic polymorphisms at the 16th (Arg-Gly) and 27th (GlnGlu) amino acid positions of the ß2-adrenergic receptor (ADRB2) may be linked to various asthma-related phenotypes. These include the adverse effects on lung function known to occur following the regular use of albuterol. The study aimed to determine the association between these two ADRB2 SNPs, their haplotypes and the phenotypes in Thai asthmatic patients. One-hundred and thirty asthmatic patients were genotyped at the Arg16Gly and Gln27Glu polymorphisms. Demographic data, disease severities, pulmonary function tests and medication usages were recorded for each patient. The frequencies of the Arg16 and Gln27 alleles were found to be 56.9% and 91.2%, respectively, while the linkage disequilibrium coefficient between the two SNPs was 0.36. Three haplotypes were estimated, i.e. Arg-Gln, Gly-Gln and Gly-Glu with frequencies of 148 (56.9%), 89 (34.2%) and 23 (8.9%), respectively. The mean percentages for predicted FEV1 (%FEV1) for these corresponding haplotypes were 73.5 (SD = 16.3), 72.4 (SD = 17.4)and 80.7 (SD = 13.1), respectively (p = 0.258). Additionally, the number of hospitalizations, emergency visits and inhaled corticosteroid/longacting ß2-agonist (ICS/ LABA) usages were lower in Gln/Glu subjects than for Gln/Gln genotyped patients, with values of 0% versus 11.9% (p = 0.122) for hospitalizations;4.5% versus 18.8% (p = 0.121) for emergency visits; and 50% versus 76.6%, (p = 0.042) for ICS/LABA usages. The presence of the Glu27 allele in Thai asthmatic patients is associated with a decreased asthma severity, higher %FEV1 values, less frequent hospitalizations and emergency visits, and decreased ICS/LABA usage.

Virological and immunological responses of efavirenz-based HAART regimen initiated in HIV-infected patients at CD4 < 100 versus CD4 > or = 100 cells/mm3.

OBJECTIVE: To compare virological and immunological responsiveness of efavirenz (EFV)-based highly active anti retroviral therapy (HAART) between patients with baseline CD4 < 100 and CD4 > or = 100 cells/mm3. MATERIAL AND METHOD: A prospective cohort study in antiretroviral-naive HIV-infected patients was conducted between February and April 2002. Donated HAART regimen, consisting of stavudine, didanosine, and EFV was initiated. The primary outcome was time to undetectable HIV RNA, < 50 copies/mL. Patients were followed up every 12 weeks until 48 weeks (the end of the study). RESULTS: Forty-six patients were included, 21 patients for CD4 < 100 cells/mm3 and 25 patients for CD4 > or = 100 cells/mm3. Median CD4 cell counts of these corresponding groups were 26.5 and 177 cells/mm3. Patients' characteristics were similar between the two groups except CD4. The probability of undetectable HIV RNA at 12, 24, 36, and 48 weeks were 57.1% (95% CI, 37.7-78.1%), 76.2% (95% CI, 56.9-91.3%), 80.9% (95% CI, 62.3-94.0%), and 90.5% (95% CI, 68.9-99.1%) for the former group; and 64.0% (95% CI, 45.8-81.8%), 92.0% (95% CI, 77.5-98.6%), 96.0% (95% CI, 83.0-99.7%), and 96.0%.(95% CI, 83.0-99.7%) for the latter group. Median time to undetectable HIV RNA was 12 weeks for both groups. Median CD4 change at 48 weeks was 171 and 132 cells/mm3, respectively (p = 0.232). The adverse events were similar between the two groups. CONCLUSION: Initiation of EFV-based HAART regimen in HIV-infected patients at CD4 < 100 and > or = 100 cells/ mm3 gains similar immunological and virological response.

Prevalence of hepatitis B virus and hepatitis C virus co-infection with human immunodeficiency virus in Thai patients: a tertiary-care-based study.

BACKGROUND: Hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV share the route of transmission. HBV or HCV co-infection with HIV has been associated with a reduced survival rate, an increased risk of progression to severe liver disease, and an increased risk of hepatotoxicity associated with active antiretroviral therapy. Information regarding prevalence of HBV and HCV co-infection with HIV in Thailand is limited. PATIENTS AND METHOD: A cross-sectional study of prevalence and risk factors of HBV and HCV co-infection in HIV-infected patients was conducted. All HIV-infected patients who were cared for in March 2003 at Ramathibodi Hospital were included. RESULTS: There were 529 HIV-infected patients with a mean age of 36.7 years and 56.5% males. Of these, 58.8% lived in Bangkok, whereas, the others were from provincial areas. Heterosexual contact were the acquisition of HIV infection in 98.1% of all patients. The prevalence of HBV infection was 8.7%, and HCV infection was 7.8%. There was no difference between the prevalence of these infections in Bangkok and provincial areas (p = 0.115). History of intravenous drug use was associated with both HBV and HCV co-infection (p < 0.001). HCV co-infection group was also associated with male gender (p = 0.002) and elevated serum alanine transaminase (ALT) level (p = 0.0003). CONCLUSIONS: The prevalence of HBV and HCV co-infection with HIV in Thai patients is significant. In the author s resources-limited setting, history of intravenous drug use is a major indicator to screen for both HBV and HCV co-infection. Male gender and elevated serum ALT level are also suggestive of HCV co-infection.

Long-term outcome and factors influencing the outcome of thymectomy for myasthenia gravis.

Thymectomy has gained widespread acceptance as a treatment for patients with myasthenia gravis (MG). Patients with myasthenia gravis who had undergone thymectomy by extended transsternal approach between 1981 and 1987 were retrospectively reviewed to evaluate the result of thymectomy, time to remission, time to maximum improvement and factors influencing remission after thymectomy. There were 128 patients, 45 men and 83 women and the mean ages at the time of thymectomy were 35.7 and 32.2 years respectively. After thymectomy, 41.2% of the patients were in remission, 53% improved and 5.8% had no response. The remission rates at 1, 2, 5 and 10 years after thymectomy were 9%, 17%, 37% and 53% respectively and the median time to remission was 9 years. The maximum improvement rates at 1, 2, 5 and 10 years after thymectomy were estimated to be 30%, 40%, 57% and 78% respectively and the median time to maximum improvement was 3.6 years. Patients with ocular MG, longer duration of symptoms before thymectomy and atrophic thymus gland appeared to take longer to achieve remission although none of the factors was significantly associated with the time to remission. Thymectomy is beneficialfor MG patients with satisfactory remission and improvement rates. It is recommended that thymectomy should be advocatedfor these patients early in the course of the disease because the duration of the symptoms appeared to be the main determinant of the outcome.

Earlier onset of pubertal maturation in Thai girls.

BACKGROUND: Recent studies in the USA and Hong Kong demonstrated the onset of puberty in girls has shifted toward a younger age. Based upon previous studies on variations of pubertal maturation in Thai girls, the secular trend has also moved toward an earlier age. The latest study in 1995 revealed the mean age of menarche was 12.3 years. OBJECTIVES: To identify the onset of puberty, menarche and pubarche in female children and adolescents in 2 Bangkok schools. METHOD: Three hundred school girls aged 9-19 years were enrolled in the study. Data were collected from January 1997 through December 1999. Assessment of pubertal staging by Tanner's criteria was performed by a trained pediatrician. All were in good physical health and had normal height and weight. The median ages of thelarche, menarche and pubarche were estimated by probit analysis. All other parameters were expressed as mean +/- SD. RESULTS: The median ages of thelarche and pubarche were 9.4 and 11.1 years, respectively. Two hundred and twenty one girls had experienced menstruation. The median age of menarche was 11.2 years, whereas, the mean age was 12.1 years. Most girls reached near final adult height after 14 years old. CONCLUSION: The secular trend in decline of the ages of thelarche (or puberty) and menarche was observed in Bangkok girls. Further study in a larger population including a younger age group is required to define the current reference interval of onset of puberty.

Correlation between susceptibility of Mycobacterium tuberculosis by microtiter plate alamar blue assay and clinical outcomes.

A rapid, inexpensive, and reliable antimycobacterial susceptibility assay is needed to effectively deal with the increasing prevalence of resistant strains of M. tuberculosis in Thailand. The microtiter plate Alamar blue assay (MABA) appears to be promising but requires additional data regarding correlation with clinical outcome. The correlation between the susceptibility by MABA and clinical outcomes was studied. There were 123 specimens obtained from extra-pulmonary sites of 108 patients at Ramathibodi Hospital in 1999. The authors found that susceptibility of M. tuberculosis isolates by the MABA correlated with the clinical outcome; patients with isolates sensitive to isoniazid, rifampicin, and ethambutol had a better clinical outcome than patients with isolates resistant to at least one of these drugs (p=0.004). Studies to determine this correlation in pulmonary tuberculosis are still needed.