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1. Effect of Pneumococcal Conjugate Vaccine on Pneumonia Incidence Rates among Children 2-59 Months of Age, Mongolia, 2015-2021

Author

von Mollendorf, Claire, Ulziibayar, Munkhchuluun, Nguyen, Cattram D., Batsaikhan, Purevsuren, Suuri, Bujinlkham, Luvsantseren, Dashtseren, Narangerel, Dorj, de Campo, John, de Campo, Margaret, Tsolmon, Bilegtsaikhan, Demberelsuren, Sodbayar, Dunne, Eileen M., Satzke, Catherine, Mungun, Tuya, and Mulholland, E. Kim

Subjects
Conjugate vaccines -- Statistics -- Patient outcomes, Pneumonia in children -- Statistics -- Prevention -- Patient outcomes, Pneumococcal vaccine -- Statistics -- Patient outcomes, Pediatric research, Health
Abstract

Globally, the most common infectious cause of death among children 1-59 months of age is lower respiratory tract infection (1). Despite vaccine availability, Streptococcus pneumoniae causes a substantial proportion of [...]

Published
2024
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4. Effect of pneumococcal conjugate vaccine six years post-introduction on pneumococcal carriage in Ulaanbaatar, Mongolia

Author

von Mollendorf, Claire, Mungun, Tuya, Ulziibayar, Munkhchuluun, Skoko, Paige, Boelsen, Laura, Nguyen, Cattram, Batsaikhan, Purevsuren, Suuri, Bujinlkham, Luvsantseren, Dashtseren, Narangerel, Dorj, Tsolmon, Bilegtsaikhan, Demberelsuren, Sodbayar, Ortika, Belinda D., Pell, Casey L., Wee-Hee, Ashleigh, Nation, Monica L., Hinds, Jason, Dunne, Eileen M., Mulholland, E. Kim, and Satzke, Catherine

Published
2024
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6. Evaluation of multiple imputation to address intended and unintended missing data in case-cohort studies with a binary endpoint

Author

Middleton, Melissa, Nguyen, Cattram, Carlin, John B., Moreno-Betancur, Margarita, and Lee, Katherine J.

Subjects
Statistics - Methodology
Abstract

Case-cohort studies are conducted within cohort studies, wherein collection of exposure data is limited to a subset of the cohort, leading to a large proportion of missing data by design. Standard analysis uses inverse probability weighting (IPW) to address this intended missing data, but little research has been conducted into how best to perform analysis when there is also unintended missingness. Multiple imputation (MI) has become a default standard for handling unintended missingness, but when used in combination with IPW, the imputation model needs to take account of the weighting to ensure compatibility with the analysis model. Alternatively, MI could be used to handle both the intended and unintended missingness. While the performance of a solely MI approach has been investigated in the context of a case-cohort study with a time-to-event outcome, it is unclear how this approach performs with binary outcomes. We conducted a simulation study to assess and compare the performance of approaches using only MI, only IPW, and a combination of MI and IPW, for handling intended and unintended missingness in this setting. We also applied the approaches to a case study. Our results show that the combined approach is approximately unbiased for estimation of the exposure effect when the sample size is large, and was the least biased with small sample sizes, while MI-only or IPW-only exhibited larger biases in both sample size settings. These findings suggest that MI is the preferred approach to handle intended and unintended missing data in case-cohort studies with binary outcomes.

Published
2022

7. A comparison of strategies for selecting auxiliary variables for multiple imputation

Author

Mainzer, Rheanna M., Nguyen, Cattram D., Carlin, John B., Moreno-Betancur, Margarita, White, Ian R., and Lee, Katherine J.

Subjects
Statistics - Methodology
Abstract

Multiple imputation (MI) is a popular method for handling missing data. Auxiliary variables can be added to the imputation model(s) to improve MI estimates. However, the choice of which auxiliary variables to include in the imputation model is not always straightforward. Including too few may lead to important information being discarded, but including too many can cause problems with convergence of the estimation procedures for imputation models. Several data-driven auxiliary variable selection strategies have been proposed. This paper uses a simulation study and a case study to provide a comprehensive comparison of the performance of eight auxiliary variable selection strategies, with the aim of providing practical advice to users of MI. A complete case analysis and an MI analysis with all auxiliary variables included in the imputation model (the full model) were also performed for comparison. Our simulation study results suggest that the full model outperforms all auxiliary variable selection strategies, providing further support for adopting an inclusive auxiliary variable strategy where possible. Auxiliary variable selection using the Least Absolute Selection and Shrinkage Operator (LASSO) was the best performing auxiliary variable selection strategy overall and is a promising alternative when the full model fails. All MI analysis strategies that we were able to apply to the case study led to similar estimates., Comment: 30 pages, 3 figures, 1 table

Published
2022

8. Impact of pneumococcal conjugate vaccine 13 introduction on severe lower respiratory tract infections associated with respiratory syncytial virus or influenza virus in hospitalized children in Ulaanbaatar, Mongolia

Author

Do, Lien Anh Ha, Tsedenbal, Naranzul, Khishigmunkh, Chimidregzen, Tserendulam, Bazarkhuu, Altanbumba, Lkhagvadorj, Luvsantseren, Dashtseren, Ulziibayar, Munkhchuluun, Suuri, Bujinlkham, Narangerel, Dorj, Tsolmon, Bilegtsaikhan, Demberelsuren, Sodbayar, Nguyen, Cattram, Mungun, Tuya, von Mollendorf, Claire, Badarch, Darmaa, and Mulholland, Kim

Published
2024
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10. Impact of the COVID-19 pandemic on a clinical trial of pneumococcal vaccine scheduling (PVS) in rural Gambia

Author

Hossain, Ilias, Osei, Isaac, Lobga, Galega, Wutor, Baleng M., Olatunji, Yekini, Adefila, Williams, Adeshola, Banjo, Isa, Yasir, Nguyen, Cattram, Sonko, Kemo, Ceesay, Lamin, Baldeh, Bubacarr, Barrow, Omar, Young, Benjamin, Ceesay, Saidina, Nyassi, Abdoullah, Sarwar, Golam, Barjo, Ousman, M.Drammeh, Momodou, Salaudeen, Rasheed, and Mackenzie, Grant

Published
2023
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11. Impact of childhood 13-valent pneumococcal conjugate vaccine introduction on adult pneumonia hospitalisations in Mongolia: a time series analysis

Author

Fagerli, Kirsten, Ulziibayar, Munkhchuluun, Suuri, Bujinlkham, Luvsantseren, Dashtseren, Narangerel, Dorj, Batsaikhan, Purevsuren, Tsolmon, Bilegtsaikhan, de Campo, John, de Campo, Margaret, Dunne, Eileen M., Allen, Kristen E., Grobler, Anneke C., Nguyen, Cattram D., Gessner, Bradford D., Mungun, Tuya, Mulholland, E. Kim, and von Mollendorf, Claire

Published
2024
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12. Immunogenicity, safety, and reactogenicity of a half- versus full-dose BNT162b2 (Pfizer-BioNTech) booster following a two-dose ChAdOx1 nCoV-19, BBIBP-CorV, or Gam-COVID-Vac priming schedule in Mongolia: a randomised, controlled, non-inferiority trial

Author

Batmunkh, Tsetsegsaikhan, Moore, Kerryn A., Thomson, Helen, Altangerel, Bolor, Amraa, Otgonjargal, Avaa, Naranbaatar, Batbayar, Lkhagvagaram, Batsukh, Khishigjargal, Bright, Kathryn, Burentogtokh, Tsogjargal, Ha Do, Lien Anh, Dorj, Gantuya, Hart, John D., Javkhlantugs, Khulan, Jigjidsuren, Sarantsetseg, Justice, Frances, Li, Shuo, Licciardi, Paul V., Mashbaatar, Khaliunaa, Mazarakis, Nadia, Neal, Eleanor F.G., Nguyen, Cattram Duong, Ochirbat, Batbayar, Tsolmon, Bilegtsaikhan, Tuya, Alimaa, Surenjav, Unursaikhan, von Mollendorf, Claire, and Mulholland, Kim

Published
2024
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13. A single dose of quadrivalent HPV vaccine is highly effective against HPV genotypes 16 and 18 detection in young pregnant women eight years following vaccination: an retrospective cohort study in Fiji

Author

Reyburn, Rita, Tuivaga, Evelyn, Ratu, Tupou, Young, Seruwaia, Garland, Suzanne M., Murray, Gerald, Cornall, Alyssa, Tabrizi, Sepehr, Nguyen, Cattram D., Jenkins, Kylie, Tikoduadua, Lisi, Kado, Joseph, Kama, Mike, Rafai, Eric, Devi, Rachel, Mulholland, Kim, Fong, James, and Russell, Fiona M.

Published
2023
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14. Efficacy against pneumococcal carriage and the immunogenicity of reduced-dose (0 + 1 and 1 + 1) PCV10 and PCV13 schedules in Ho Chi Minh City, Viet Nam: a parallel, single-blind, randomised controlled trial

Author

Balloch, Anne, Beissbarth, Jemima, Bright, Kathryn, Higgins, Rachel Ann, Hinds, Jason, Hoan, Pham Thi, Nation, Monica Larissa, Nguyen, Cattram Duong, Ortika, Belinda Daniela, Phan, Thanh V, Phuong, Tran Linh, Spry, Leena, Thuy, Ho Nguyen Loc, Toan, Nguyen Trong, Uyen, Doan Y, Vy, Le Thi Tuong, Temple, Beth, Tran, Hau Phuc, Dai, Vo Thi Trang, Smith-Vaughan, Heidi, Licciardi, Paul Vincent, Satzke, Catherine, Nguyen, Thuong Vu, and Mulholland, Kim

Published
2023
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15. Immunogenicity and safety in healthy adults of full dose versus half doses of COVID-19 vaccine (ChAdOx1-S or BNT162b2) or full-dose CoronaVac administered as a booster dose after priming with CoronaVac: a randomised, observer-masked, controlled trial in Indonesia

Author

Sofiatin, Yulia, Suryadinata, Hendarsyah, Hartantri, Yovita, Sukandar, Hadyana, Indrati, Agnes Rengga, Murad, Chrysanti, Setiawaty, Vivi, Pangesti, Krisna Nur Andriana, Multihartina, Pretty, Khrisna, Citra Vravita, Ayuninda, Masayu Riela, Wicaksana, Pratama, Zhafira, Aqila Sakina, Sinto, Robert, Rusmil, Kusnandi, Sundoro, Julitasari, Watts, Emma, Nguyen, Cattram, Fadlyana, Eddy, Setiabudi, Djatnika, Kartasasmita, C B, Putri, Nina Dwi, Rezeki Hadinegoro, Sri, and Mulholland, Kim

Published
2023
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16. Effect of different schedules of ten-valent pneumococcal conjugate vaccine on pneumococcal carriage in Vietnamese infants: results from a randomised controlled trial

Author

Smith-Vaughan, Heidi, Temple, Beth, Trang Dai, Vo Thi, Hoan, Pham Thi, Loc Thuy, Ho Nguyen, Phan, Thanh V., Bright, Kathryn, Toan, Nguyen Trong, Uyen, Doan Y., Nguyen, Cattram Duong, Beissbarth, Jemima, Ortika, Belinda Daniela, Nation, Monica Larissa, Dunne, Eileen Margaret, Hinds, Jason, Lai, Jana, Satzke, Catherine, Huu, Tran Ngoc, and Mulholland, Kim

Published
2023
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18. Memory B cell responses induced by pneumococcal conjugate vaccine schedules with fewer doses: analysis of a randomised-controlled trial in Viet Nam

Author

Ong, Darren, primary, Thanh, Phan Van, additional, Temple, Beth, additional, Toh, Zheng Quan, additional, Nguyen, Cattram, additional, Vientrung, Kien, additional, Nguyen, Hoang Van Anh, additional, Dai , Vo Thi Trang, additional, Bright, Kathryn, additional, Tran, Hau Phuc, additional, Higgins, Rachel, additional, Cheung, Yin Bun, additional, Nguyen, Thuong, additional, Mulholland, Kim, additional, and Licciardi, Paul, additional

Published
2024
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24. Preventing postnatal depression in new mothers using telephone peer support: protocol for the DAISY (Depression and AnxIety peer Support studY) multi-centre randomised controlled trial

Author

Shafiei, Touran, primary, McLachlan, Helen L, additional, Dennis, Cindy-Lee, additional, Nicholson, Jan M, additional, Nguyen, Tram, additional, Shiell, Alan, additional, Nguyen, Cattram D, additional, Grimes, Heather, additional, Bee, Jessica, additional, Adams, Catina, additional, Callander, Emily, additional, and Forster, Della A, additional

Published
2024
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25. Impact of pneumococcal conjugate vaccine 13 (PCV13) introduction on severe lower respiratory tract infections associated with respiratory syncytial virus or influenza virus in hospitalised children in Ulaanbaatar, Mongolia.

Author

Do, Lien Anh Ha, primary, Tsedenbal, Naranzul, additional, Khishigmunkh, Chimidregzen, additional, Tserendulam, Bazarkhuu, additional, Altanbumba, Lkhagvadorj, additional, Luvsantseren, Dashtseren, additional, Ulziibayar, Munkhchuluun, additional, Suuri, Bujinlkham, additional, Narangerel, Dorj, additional, Tsolmon, Bilegtsaikhan, additional, Demberelsuren, Sodbayar, additional, Nguyen, Cattram, additional, Mungun, Tuya, additional, von Mollendorf, Claire, additional, Badarch, Darmaa, additional, and Mulholland, Kim, additional

Published
2024
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26. Immunogenicity and impact on nasopharyngeal carriage of a single dose of PCV10 given to vietnamese children at 18 months of age

Author

Higgins, Rachel A, Temple, Beth, Dai, Vo Thi Trang, Phan, Thanh V, Toan, Nguyen Trong, Spry, Leena, Toh, Zheng Quan, Nation, Monica L, Ortika, Belinda D, Uyen, Doan Y, Cheung, Yin Bun, Nguyen, Cattram D, Bright, Kathryn, Hinds, Jason, Balloch, Anne, Smith-Vaughan, Heidi, Huu, Tran Ngoc, Mulholland, Kim, Satzke, Catherine, and Licciardi, Paul V

Published
2021
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30. Evaluation of a multiplex-qPCR for paediatric pleural empyema—An observational study in hospitalised children.

Author

Jacobson, Jonathan, Fabri, Loraine, Osowicki, Joshua, Shanthikumar, Shivanthan, Costa, Anna-Maria, Ortika, Belinda, Wee-Hee, Ashleigh, Pragassen, Michelle, Gatt, Cassandra, Gonis, Gena, Nguyen, Cattram, Rozen, Thomas, Teague, Warwick, Buttery, Jim, Clifford, Vanessa, Mulholland, Kim, Steer, Andrew, Ranganathan, Sarath, Daley, Andrew, and Dunne, Eileen

Subjects
EMPYEMA, BACTERIAL cultures, STREPTOCOCCUS pneumoniae, STREPTOCOCCUS pyogenes, SCIENTIFIC observation, HAEMOPHILUS influenzae, STAPHYLOCOCCUS aureus
Abstract

Pleural empyema is a serious complication of pneumonia in children. Negative bacterial cultures commonly impede optimal antibiotic therapy. To improve bacterial identification, we developed a molecular assay and evaluated its performance compared with bacterial culture. Our multiplex-quantitative PCR to detect Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Haemophilus influenzae was assessed using bacterial genomic DNA and laboratory-prepared samples (n = 267). To evaluate clinical performance, we conducted the Molecular Assessment of Thoracic Empyema (MATE) observational study, enrolling children hospitalised with empyema. Pleural fluids were tested by bacterial culture and multiplex-qPCR, and performance determined using a study gold standard. We determined clinical sensitivity and time-to-organism-identification to assess the potential of the multiplex-qPCR to reduce the duration of empiric untargeted antibiotic therapy. Using spiked samples, the multiplex-qPCR demonstrated 213/215 (99.1%) sensitivity and 52/52 (100%) specificity for all organisms. During May 2019–March 2023, 100 children were enrolled in the MATE study; median age was 3.9 years (IQR 2–5.6). A bacterial pathogen was identified in 90/100 (90%) specimens by multiplex-qPCR, and 24/100 (24%) by bacterial culture (P <0.001). Multiplex-qPCR identified a bacterial cause in 68/76 (90%) culture-negative specimens. S. pneumoniae was the most common pathogen, identified in 67/100 (67%) specimens. We estimate our multiplex-qPCR would have reduced the duration of untargeted antibiotic therapy in 61% of cases by a median 20 days (IQR 17.5–23, range 1–55). Multiplex-qPCR significantly increased pathogen detection compared with culture and may allow for reducing the duration of untargeted antibiotic therapy. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Evaluation of the impact of childhood 13-valent pneumococcal conjugate vaccine introduction on adult pneumonia in Ulaanbaatar, Mongolia: study protocol for an observational study

Author

von Mollendorf, Claire, Ulziibayar, Mukhchuluun, Gessner, Bradford D., Do, Lien Anh Ha, Nguyen, Cattram D., Beavon, Rohini, Suuri, Bujinlkham, Luvsantseren, Dashtseren, Narangerel, Dorj, Jenney, Adam, Dunne, Eileen M., Satzke, Catherine, Darmaa, Badarchiin, Mungun, Tuya, and Mulholland, E. Kim

Published
2021
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36. Effect of ten-valent pneumococcal conjugate vaccine introduction on pneumococcal carriage in Fiji: results from four annual cross-sectional carriage surveys

Author

Dunne, Eileen M, Satzke, Catherine, Ratu, Felisita T, Neal, Eleanor F G, Boelsen, Laura K, Matanitobua, Silivia, Pell, Casey L, Nation, Monica L, Ortika, Belinda D, Reyburn, Rita, Jenkins, Kylie, Nguyen, Cattram, Gould, Katherine, Hinds, Jason, Tikoduadua, Lisi, Kado, Joseph, Rafai, Eric, Kama, Mike, Mulholland, E Kim, and Russell, Fiona M

Published
2018
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37. Respiratory Syncytial Virus and Influenza Infections in Children in Ulaanbaatar, Mongolia, 2015–2021.

Author

Do, Lien Anh Ha, Tsedenbal, Naranzul, Khishigmunkh, Chimidregzen, Tserendulam, Bazarkhuu, Altanbumba, Lkhagvadorj, Luvsantseren, Dashtseren, Ulziibayar, Munkhchuluun, Suuri, Bujinlkham, Narangerel, Dorj, Tsolmon, Bilegtsaikhan, Demberelsuren, Sodbayar, Pell, Casey L, Manna, Sam, Satzke, Catherine, Nguyen, Cattram, Mungun, Tuya, von Mollendorf, Claire, Badarch, Darmaa, and Mulholland, Kim

Subjects
RESPIRATORY syncytial virus infections, PNEUMOCOCCAL pneumonia, RESPIRATORY infections, INFLUENZA viruses, INFLUENZA, PNEUMOCOCCAL vaccines
Abstract

Background: Data available for RSV and influenza infections among children < 2 years in Mongolia are limited. We present data from four districts of Ulaanbaatar from April 2015 to June 2021. Methods: This study was nested in an enhanced surveillance project evaluating pneumococcal conjugate vaccine (PCV13) impact on the incidence of hospitalized lower respiratory tract infections (LRTIs). Our study was restricted to children aged < 2 years with arterial O2 saturation < 93% and children with radiological pneumonia. Nasopharyngeal (NP) swabs collected at admission were tested for RSV and influenza using qRT‐PCR. NP swabs of all patients with radiological pneumonia and of a subset of randomly selected NP swabs were tested for S. pneumoniae (S.p.) by qPCR and for serotypes by culture and DNA microarray. Results: Among 5705 patients, 2113 (37.0%) and 386 (6.8%) had RSV and influenza infections, respectively. Children aged 2–6 months had a higher percentage of very severe RSV infection compared to those older than 6 months (42.2% versus 31.4%, p‐value Fisher's exact = 0.001). S.p. carriage was detected in 1073/2281 (47.0%) patients. Among S.p. carriage cases, 363/1073 (33.8%) had S.p. and RSV codetection, and 82/1073 (7.6%) had S.p. and influenza codetection. S.p. codetection with RSV/influenza was not associated with more severe LRTIs, compared to only RSV/influenza cases. Conclusion: In Mongolia, RSV is an important pathogen causing more severe LRTI in children under 6 months of age. Codetection of RSV or influenza virus and S.p. was not associated with increased severity. [ABSTRACT FROM AUTHOR]

Published
2024
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40. Sustained Antibody Responses 6 Years Following 1, 2, or 3 Doses of Quadrivalent Human Papillomavirus (HPV) Vaccine in Adolescent Fijian Girls, and Subsequent Responses to a Single Dose of Bivalent HPV Vaccine: A Prospective Cohort Study

Author

Toh, Zheng Quan, Russell, Fiona M., Reyburn, Rita, Fong, James, Tuivaga, Evelyn, Ratu, Tupou, Nguyen, Cattram D., Devi, Rachel, Kama, Mike, Matanitobua, Silivia, Tabrizi, Sepehr N., Garland, Suzanne M., Sinha, Rohit, Frazer, Ian, Tikoduadua, Lisi, Kado, Joseph, Rafai, Eric, Mulholland, Edward K., and Licciardi, Paul V.

Published
2017

41. Efficacy against pneumococcal carriage and the immunogenicity of reduced-dose (0 + 1 and 1 + 1) PCV10 and PCV13 schedules in Ho Chi Minh City, Viet Nam: a parallel, single-blind, randomised controlled trial

Author

Temple, Beth, primary, Tran, Hau Phuc, additional, Dai, Vo Thi Trang, additional, Smith-Vaughan, Heidi, additional, Licciardi, Paul Vincent, additional, Satzke, Catherine, additional, Nguyen, Thuong Vu, additional, Mulholland, Kim, additional, Balloch, Anne, additional, Beissbarth, Jemima, additional, Bright, Kathryn, additional, Higgins, Rachel Ann, additional, Hinds, Jason, additional, Hoan, Pham Thi, additional, Nation, Monica Larissa, additional, Nguyen, Cattram Duong, additional, Ortika, Belinda Daniela, additional, Phan, Thanh V, additional, Phuong, Tran Linh, additional, Spry, Leena, additional, Thuy, Ho Nguyen Loc, additional, Toan, Nguyen Trong, additional, Uyen, Doan Y, additional, and Vy, Le Thi Tuong, additional

Published
2023
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44. Temporal decline in diarrhea episodes and mortality in Kiribati children two years following rotavirus vaccine introduction, despite high malnutrition rates: a retrospective review

Author

Lai, Jana, Nguyen, Cattram, Tabwaia, Beia, Nikuata, Agnes, Baueri, Nikarawa, Timeon, Eretii, Diaaldeen, Mohammed, Iuta, Tinai, Ozturk, Murat Hakan, Moore, Aaron, Hall, Alice, Nyambat, Batmunkh, Davis, Stephanie, Rahman, Ataur, Erasmus, Wendy, Fox, Kimberley, and Russell, Fiona

Published
2020
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45. Levels of pneumococcal conjugate vaccine coverage and indirect protection against invasive pneumococcal disease and pneumonia hospitalisations in Australia: An observational study

Author

Chan, Jocelyn, Gidding, Heather F., Blyth, Christopher C., Fathima, Parveen, Jayasinghe, Sanjay, McIntyre, Peter B., Moore, Hannah C., Mulholland, Kim, Nguyen, Cattram D., Andrews, Ross, and Russell, Fiona M.

Subjects
Pneumonia in children -- Prevention -- Statistics, Pneumococcal vaccine -- Usage -- Evaluation, Pediatric research, Biological sciences
Abstract

Background There is limited empiric evidence on the coverage of pneumococcal conjugate vaccines (PCVs) required to generate substantial indirect protection. We investigate the association between population PCV coverage and indirect protection against invasive pneumococcal disease (IPD) and pneumonia hospitalisations among undervaccinated Australian children. Methods and findings Birth and vaccination records, IPD notifications, and hospitalisations were individually linked for children aged There were strong inverse associations between PCV coverage and the incidence of PCV7-type IPD (adjusted incidence rate ratio [aIRR] 0.967, 95% confidence interval [CI] 0.958 to 0.975, p-value < 0.001), and pneumonia hospitalisations (all-cause pneumonia: aIRR 0.991 95% CI 0.990 to 0.994, p-value < 0.001) among undervaccinated children. Subgroup analyses for children Conclusions In this study, we observed substantial indirect protection at lower levels of PCV coverage than previously described-challenging assumptions that high levels of PCV coverage (i.e., greater than 90%) are required. Understanding the association between PCV coverage and indirect protection is a priority since the control of vaccine-type pneumococcal disease is a prerequisite for reducing the number of PCV doses (from 3 to 2). Reduced dose schedules have the potential to substantially reduce program costs while maintaining vaccine impact., Author(s): Jocelyn Chan 1,2,*, Heather F. Gidding 3,4,5, Christopher C. Blyth 6, Parveen Fathima 7, Sanjay Jayasinghe 5,8, Peter B. McIntyre 5, Hannah C. Moore 7, Kim Mulholland 1,2,9, Cattram [...]

Published
2021
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46. Immunogenicity and safety in healthy adults of full dose versus half doses of COVID-19 vaccine (ChAdOx1-S or BNT162b2) or full-dose CoronaVac administered as a booster dose after priming with CoronaVac: a randomised, observer-masked, controlled trial in Indonesia

Author

Fadlyana, Eddy, primary, Setiabudi, Djatnika, additional, Kartasasmita, C B, additional, Putri, Nina Dwi, additional, Rezeki Hadinegoro, Sri, additional, Mulholland, Kim, additional, Sofiatin, Yulia, additional, Suryadinata, Hendarsyah, additional, Hartantri, Yovita, additional, Sukandar, Hadyana, additional, Indrati, Agnes Rengga, additional, Murad, Chrysanti, additional, Setiawaty, Vivi, additional, Pangesti, Krisna Nur Andriana, additional, Multihartina, Pretty, additional, Khrisna, Citra Vravita, additional, Ayuninda, Masayu Riela, additional, Wicaksana, Pratama, additional, Zhafira, Aqila Sakina, additional, Sinto, Robert, additional, Rusmil, Kusnandi, additional, Sundoro, Julitasari, additional, Watts, Emma, additional, and Nguyen, Cattram, additional

Published
2023
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48. A culturally competent systems intervention in primary health care to reduce domestic violence among immigrant communities: HARMONY a pragmatic cluster-randomised controlled trial in Melbourne, Australia

Author

Taft, Angela, primary, Hegarty, Kelsey, additional, Yelland, Jane, additional, Mazza, Danielle, additional, Norman, Richard, additional, Feder, Gene, additional, Boyle, Douglas, additional, Nguyen, Cattram, additional, Garcia-Moreno, Claudia, additional, Young, Felicity, additional, Pokharel, Bijaya, additional, and Allen-Leap, Molly, additional

Published
2023
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49. Evaluation of the effect of reduced-dose pneumococcal conjugate vaccine schedules on vaccine serotype carriage in children and their caretakers in a naïve population in Vietnam: Protocol for a cluster randomized non-inferiority trial

Author

Yoshida, Lay-Myint, Flasche, Stefan, Mulholland, Kim, Nguyen, Hien-Anh, Nguyen, Cattram, Toizumi, Michiko, Dang, Duc-Anh, Yoshida, Lay-Myint, Flasche, Stefan, Mulholland, Kim, Nguyen, Hien-Anh, Nguyen, Cattram, Toizumi, Michiko, and Dang, Duc-Anh

Abstract

Introduction: The WHO currently recommends giving pneumococcal conjugate vaccines (PCVs) as three doses – either three doses in infancy with Pentavalent vaccine (3p+0), or two doses in infancy followed by a booster around 12 months (2p+1). However, their high price is a barrier to introduction and sustainability in low and middle-income countries. We hypothesize that a schedule with a single priming and a booster dose (1p+1) may maintain similar levels of protection for the community by sustaining herd immunity, once circulation of vaccine types has been controlled. Methods and analysis: We will conduct a cluster randomized trial with four intervention arms (1p+1, 0p+1, 2p+1, 3p+0) and three unvaccinated clusters in the 27 communes of Nha Trang, central Vietnam. A PCV catch-up vaccination campaign to all children under three years of age will be performed at the start of the trial. The primary endpoint is non-inferiority of the1p+1 schedule if compared to the WHO standard 2p+1 and 3p+0 schedules in reducing vaccine serotype carriage prevalence in infants. We will also explore impact of 0p+1 schedule. A baseline and annual pneumococcal carriage surveys of 6480 participants per survey covering infants, toddlers and their mothers will be conducted. Ethics and dissemination: Ethical approvals were obtained from the ethical review committees of Institute of Tropical Medicine, Nagasaki University (151203149-2) and the Ministry of Health, Vietnam (1915/QD-BYT). The results, interpretation and conclusions will be presented at national and international conferences, and published in peer-reviewed open access journals., Gates Open Research, 7, art. no. 110; 2023

Published
2023

50. Evaluation of multiple imputation to address intended and unintended missing data in case-cohort studies with a binary endpoint

Author

Middleton, Melissa, Nguyen, Cattram, Carlin, John B., Moreno-Betancur, Margarita, and Lee, Katherine J.

Subjects
Methodology (stat.ME), FOS: Computer and information sciences, Statistics - Methodology
Abstract

Background: Case-cohort studies are conducted within cohort studies, with the defining feature that collection of exposure data is limited to a subset of the cohort, leading to a large proportion of missing data by design. Standard analysis uses inverse probability weighting (IPW) to address this intended missing data, but little research has been conducted into how best to perform analysis when there is also unintended missingness. Multiple imputation (MI) has become a default standard for handling unintended missingness and is typically used in combination with IPW to handle the intended missingness due to the case-control sampling. Alternatively, MI could be used to handle both the intended and unintended missingness. While the performance of an MI-only approach has been investigated in the context of a case-cohort study with a time-to-event outcome, it is unclear how this approach performs with a binary outcome. Methods: We conducted a simulation study to assess and compare the performance of approaches using only MI, only IPW, and a combination of MI and IPW, for handling intended and unintended missingness in the case-cohort setting. We also applied the approaches to a case study. Results: Our results show that the combined approach is approximately unbiased for estimation of the exposure effect when the sample size is large, and was the least biased with small sample sizes, while MI-only and IPW-only exhibited larger biases in both sample size settings. Conclusions: These findings suggest that a combined MI/IPW approach should be preferred to handle intended and unintended missing data in case-cohort studies with binary outcomes.

Published
2023

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