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DSM staff profile

Dr Ariyapala Samaranayaka

PositionSenior Research Fellow
QualificationsBSc MPhil PhD
Research summaryBiostatistics

Research

As a member of the Center for Biostatistics, Ari is available for biostatistical advice to researchers in the Division of Health Sciences, University of Otago. He has experience as a biostatistician in health researches more than a decade, and has contributed to more than 50 peer-reviewed health-related publications. He has worked on a wide variety of projects involving injuries, motor vehicle traffic crashes, farm and work injuries, disabilities, large longitudinal cohort studies, cross sectional surveys, as well as on related methodological developments.

Publications

Baker, W., Samaranayaka, A., Wyeth, E., Ameratunga, S., & Derrett, S. (2019). Migrants and disability following injury: Findings from a prospective study in New Zealand. Australian & New Zealand Journal of Public Health. Advance online publication. doi: 10.1111/1753-6405.12927

McNoe, B., Schollum, J. B. W., Derrett, S., Marshall, M. R., Henderson, A., Samaranayaka, A., & Walker, R. J. (2019). Recruitment and participant baseline characteristics in the dialysis outcomes in those aged 65 years or older study. BMC Nephrology, 20, 137. doi: 10.1186/s12882-019-1328-8

Richardson, A., Samaranayaka, A., Sullivan, M., & Derrett, S. (2019). Secondary health conditions and disability among people with spinal cord injury: A prospective cohort study. Journal of Spinal Cord Medicine. Advance online publication. doi: 10.1080/10790268.2019.1581392

Wyeth, E., Lambert, M., Samaranayaka, A., Harcombe, H., Davie, G., & Derrett, S. (2019). Subsequent injuries experienced by Māori: Results from a 24-month prospective study in New Zealand. New Zealand Medical Journal, 132(1499), 23-35. Retrieved from https://www.nzma.org.nz/journal

Derrett, S., Gunter, K. E., Samaranayaka, A., Singer, S. J., Nocon, R. S., Quinn, M. T., … Chin, M. H. (2019). Development and testing of the Provider and Staff Perceptions of Integrated Care (PSPIC) survey. Medical Care Research & Review, 76(6), 807-829. doi: 10.1177/1077558717745936

Journal - Research Article

Baker, W., Samaranayaka, A., Wyeth, E., Ameratunga, S., & Derrett, S. (2019). Migrants and disability following injury: Findings from a prospective study in New Zealand. Australian & New Zealand Journal of Public Health. Advance online publication. doi: 10.1111/1753-6405.12927

Derrett, S., Gunter, K. E., Samaranayaka, A., Singer, S. J., Nocon, R. S., Quinn, M. T., … Chin, M. H. (2019). Development and testing of the Provider and Staff Perceptions of Integrated Care (PSPIC) survey. Medical Care Research & Review, 76(6), 807-829. doi: 10.1177/1077558717745936

Wyeth, E., Lambert, M., Samaranayaka, A., Harcombe, H., Davie, G., & Derrett, S. (2019). Subsequent injuries experienced by Māori: Results from a 24-month prospective study in New Zealand. New Zealand Medical Journal, 132(1499), 23-35. Retrieved from https://www.nzma.org.nz/journal

Richardson, A., Samaranayaka, A., Sullivan, M., & Derrett, S. (2019). Secondary health conditions and disability among people with spinal cord injury: A prospective cohort study. Journal of Spinal Cord Medicine. Advance online publication. doi: 10.1080/10790268.2019.1581392

McNoe, B., Schollum, J. B. W., Derrett, S., Marshall, M. R., Henderson, A., Samaranayaka, A., & Walker, R. J. (2019). Recruitment and participant baseline characteristics in the dialysis outcomes in those aged 65 years or older study. BMC Nephrology, 20, 137. doi: 10.1186/s12882-019-1328-8

Chan, J. E., Samaranayaka, A., & Paterson, H. (2018). Seasonal and gestational variation in perinatal depression in a prospective cohort in New Zealand. Australian & New Zealand Journal of Obstetrics & Gynaecology. Advance online publication. doi: 10.1111/ajo.12912

Taylor, J. E., Connolly, M. J., Brookland, R., & Samaranayaka, A. (2018). Understanding driving anxiety in older adults. Maturitas. Advance online publication. doi: 10.1016/j.maturitas.2018.10.008

Windner, Z., Crengle, S., de Graaf, B., Samaranayaka, A., & Derrett, S. (2018). New Zealanders' experiences and pathways to a diagnosis of bowel cancer: A cross-sectional descriptive study of a younger cohort. New Zealand Medical Journal, 131(1483), 30-39. Retrieved from https://www.nzma.org.nz/journal

Leitch, S., Dovey, S. M., Samaranayaka, A., Reith, D. M., Wallis, K. A., Eggleton, K. S., … Williamson, M. I., … Tilyard, M. W. (2018). Characteristics of a stratified random sample of New Zealand general practices. Journal of Primary Health Care. Advance online publication. doi: 10.1071/HC17089

Wyeth, E. H., Samaranayaka, A., Lambert, M., Tapsell, M., Anselm, D., Ellison, P., … Derrett, S. (2018). Understanding longer-term disability outcomes for Māori and non-Māori after hospitalisation for injury: results from a longitudinal cohort study. Public Health. Advance online publication. doi: 10.1016/j.puhe.2018.08.014

De Silva, R. K., Siriwardena, B. S. M. S., Samaranayaka, A., Abeyasinghe, W. A. M. U. L., & Tilakaratne, W. M. (2018). A model to predict nodal metastasis in patients with oral squamous cell carcinoma. PLoS ONE, 13(8), e0201755. doi: 10.1371/journal.pone.0201755

Harcombe, H., Davie, G., Wyeth, E., Samaranayaka, A., & Derrett, S. (2018). Injury upon injury: A prospective cohort study examining subsequent injury claims in the 24 months following a substantial injury. Injury Prevention, 24(6), 460-467. doi: 10.1136/injuryprev-2017-042467

Davie, G., Samaranayaka, A., & Derrett, S. (2018). The role of pre-existing comorbidity on the rate of recovery following injury: A longitudinal cohort study. PLoS ONE, 13(2), e0193019. doi: 10.1371/journal.pone.0193019

Samaranayaka, S., Walker, R. J., Samaranayaka, A., Derrett, S., & Schollum, J. B. W. (2018). Medication exposure and health outcomes in older patients with end-stage kidney disease: A prospective study undertaken in New Zealand. Drugs & Aging. Advance online publication. doi: 10.1007/s40266-018-0582-y

Hoye, N. A., Wilson, L. C., Wilkins, G. T., Jardine, D. L., Putt, T. L., Samaranayaka, A., Schollum, J. B. W., & Walker, R. J. (2017). Endovascular renal denervation in end-stage kidney disease patients: Cardiovascular protection: A proof-of-concept study. Kidney International Reports, 2(5), 856-865. doi: 10.1016/j.ekir.2017.04.012

Derrett, S., Samaranayaka, A., Schollum, J. B. W., McNoe, B., Marshall, M. R., Williams, S., Wyeth, E. H., & Walker, R. J. (2017). Predictors of health deterioration among older adults after 12 months of dialysis therapy: A longitudinal cohort study from New Zealand. American Journal of Kidney Diseases, 70(6), 798-806. doi: 10.1053/j.ajkd.2017.06.023

Page, M. J., Wyeth, E. H., Samaranayaka, A., McNoe, B., Walker, R. C., Schollum, J., … Walker, R., & Derrett, S. (2017). Accuracy of ethnicity data recorded in hospital-based patient clinical records and the Australia and New Zealand Dialysis and Transplant Registry. New Zealand Medical Journal, 130(1454), 65-71. Retrieved from https://www.nzma.org.nz/journal

Wyeth, E. H., Samaranayaka, A., Davie, G., & Derrett, S. (2017). Prevalence and predictors of disability for Māori 24 months after injury. Australian & New Zealand Journal of Public Health, 41(3), 262-268. doi: 10.1111/1753-6405.12657

Samaranayaka, C., Samaranayaka, A., Barson, D., & De Silva, R. K. (2017). Factors influencing trends in trauma-associated orbital cavity reconstruction procedures and time delay: New Zealand national data 2000–2014. Trauma, 20(4), 258-267. doi: 10.1177/1460408617719477

Harcombe, H., Samaranayaka, A., & Derrett, S. (2016). Predictors of reduced frequency of physical activity 3 months after injury: Findings from the prospective outcomes of injury study. Physical Therapy, 96(12), 1885-1895. doi: 10.2522/ptj.20160038

Nixon, G., Samaranayaka, A., de Graaf, B., McKechnie, R., Rodwell, P., & Blattner, K. (2015). The impact of a rural scanner in overcoming urban versus rural disparities in the utilisation of computed tomography. Australian Journal of Rural Health, 23, 150-154. doi: 10.1111/ajr.12125

Slatter, T. L., Hsia, H., Samaranayaka, A., Sykes, P., Clow, W., Devenish, C. J., … Royds, J. A., … Hung, N. A. (2015). Loss of ATRX and DAXX expression identifies poor prognosis for smooth muscle tumours of uncertain malignant potential and early stage uterine leiomyosarcoma. Journal of Pathology: Clinical Research, 1(2), 95-105. doi: 10.1002/cjp2.11

Langley, J. D., Lilley, R., Wilson, S., Derrett, S., Samaranayaka, A., Davie, G., … Wyeth, E. H., Hansen, P., & Hokowhitu, B. (2014). Factors associated with non-participation in one or two follow-up phases in a cohort study of injured adults. Injury Prevention, 19, 428-433. doi: 10.1136/injuryprev-2012-040685

Langley, J., Lilley, R., Samaranayaka, A., & Derrett, S. (2014). Work status and disability trajectories over 12 months after injury among workers in New Zealand. New Zealand Medical Journal, 127(1390). Retrieved from http://www.nzma.org.nz/journal

Cryer, C., Samaranayaka, A., Langley, J. D., & Davie, G. (2014). The epidemiology of life-threatening work-related injury: A demonstration paper. American Journal of Industrial Medicine, 57(4), 425-437. doi: 10.1002/ajim.22301

Wilson, S. J., Derrett, S., Cameron, I. D., Samaranayaka, A., Davie, G., & Langley, J. (2014). Prevalence of poor outcomes soon after injury and their association with the severity of the injury. Injury Prevention, 20, 57-61. doi: 10.1136/injuryprev-2012-040690

Cryer, C., Langley, J. D., Samaranayaka, A., Davie, G., Morgaine, K., Lilley, R., & Barson, D. (2014). An outcome evaluation of a New Zealand farm safety intervention: A historical cohort study. American Journal of Industrial Medicine, 57(4), 458-467. doi: 10.1002/ajim.22290

Harcombe, H., Derrett, S., Samaranayaka, A., Davie, G., Wyeth, E., & Wilson, S. (2014). Factors predictive of subsequent injury in a longitudinal cohort study. Injury Prevention, 20(6), 393-400. doi: 10.1136/injuryprev-2014-041183

Connor, J., Cousins, K., Samaranayaka, A., & Kypri, K. (2014). Situational and contextual factors that increase the risk of harm when students drink: Case-control and case-crossover investigation. Drug & Alcohol Review, 33(4), 401-411. doi: 10.1111/dar.12172

Nixon, G., Samaranayaka, A., de Graaf, B., McKechnie, R., Blattner, K., & Dovey, S. (2014). Geographic disparities in the utilisation of computed tomography scanning services in southern New Zealand. Health Policy, 118(2), 222-228. doi: 10.1016/j.healthpol.2014.05.002

Langley, J., Begg, D., Samaranayaka, A., Brookland, R., & Weiss, H. (2013). Unsupervised driving by learner licence holders: Associated characteristics and crash risk. Accident Analysis & Prevention, 60, 24-30. doi: 10.1016/j.aap.2013.07.021

Derrett, S., Wilson, S., Samaranayaka, A., Langley, J., Wyeth, E., Ameratunga, S., Lilley, R., Davie, G., & Mauiliu, M. (2013). Prevalence and predictors of disability 24-months after injury for hospitalised and non-hospitalised participants: Results from a longitudinal cohort study in New Zealand. PLoS ONE, 8(11), e80194. doi: 10.1371/journal.pone.0080194

Chalmers, D. J., Samaranayaka, A., & McNoe, B. M. (2013). Risk factors for injury in community-level football: A cohort study. International Journal of Injury Control & Safety Promotion, 20(1), 68-78. doi: 10.1080/17457300.2012.674044

Wyeth, E. H., Derrett, S., Hokowhitu, B., & Samaranayaka, A. (2013). Indigenous injury outcomes: Life satisfaction among injured Māori in New Zealand three months after injury. Health & Quality of Life Outcomes, 11, 120. doi: 10.1186/1477-7525-11-120

Langley, J., Samaranayaka, A., & Begg, D. J. (2013). Age, period and cohort effects on the incidence of motorcyclist casualties in traffic crashes. Injury Prevention, 19(3), 153-157. doi: 10.1136/injuryprev-2012-040345

Mauiliu, M., Derrett, S., Samaranayaka, A., Sopoaga, F., Kokaua, J., & Davie, G. (2013). Pacific peoples three months after injury: A comparison of outcomes between Pacific and non-Pacific participants in a NZ cohort study. Australian & New Zealand Journal of Public Health, 37(5), 463-469. doi: 10.1111/1753-6405.12124

Chalmers, D. J., Samaranayaka, A., Gulliver, P., & McNoe, B. (2012). Risk factors for injury in rugby union football in New Zealand: A cohort study. British Journal of Sports Medicine, 46(2), 95-102. doi: 10.1136/bjsports-2011-090272

Wilson, S. J., Begg, D. J., & Samaranayaka, A. (2012). Validity of using linked hospital and police traffic crash records to analyse motorcycle injury crash characteristics. Accident Analysis & Prevention, 49, 30-35. doi: 10.1016/j.aap.2011.03.007

Begg, D., Sullman, M., & Samaranayaka, A. (2012). The characteristics of young pre-licensed drivers: Evidence from the New Zealand Drivers Study. Accident Analysis & Prevention, 45, 539-546. doi: 10.1016/j.aap.2011.09.006

Langley, J., Begg, D., Brookland, R., Samaranayaka, A., Jordan, H., & Davie, G. (2012). Nonprogression through graduated driver licensing: Characteristics, traffic offending, and reasons for nonprogression. Traffic Injury Prevention, 13(1), 7-13. doi: 10.1080/15389588.2011.635170

Derrett, S., Samaranayaka, A., Wilson, S., Langley, J., Ameratunga, S., Cameron, I. D., Lilley, R., Wyeth, E., & Davie, G. (2012). Prevalence and predictors of sub-acute phase disability after injury among hospitalised and non-hospitalised groups: A longitudinal cohort study. PLoS ONE, 7(9), e44909. doi: 10.1371/journal.pone.0044909

Langley, J., Samaranayaka, A., Davie, G., & Campbell, A. J. (2011). Age, cohort and period effects on hip fracture incidence: Analysis and predictions from New Zealand data 1974-2007. Osteoporosis International, 22(1), 105-111. doi: 10.1007/s00198-010-1205-6

Davie, G., Samaranayaka, A., Langley, J. D., & Barson, D. (2011). Estimating person-based injury incidence: Accuracy of an algorithm to identify readmissions from hospital discharge data. Injury Prevention, 17(5), 338-342. doi: 10.1136/injuryprev-2011-040090

Derrett, S., Davie, G., Ameratunga, S., Wyeth, E., Colhoun, S., Wilson, S., Samaranayaka, A., Lilley, R., Hokowhitu, B., Hansen, P., & Langley, J. (2011). Prospective Outcomes of Injury Study: Recruitment, and participant characteristics, health and disability status. Injury Prevention, 17(6), 415-418. doi: 10.1136/injuryprev-2011-040044

Kypri, K., Samaranayaka, A., Connor, J., Langley, J. D., & MacLennan, B. (2011). Non-response bias in a web-based health behaviour survey of New Zealand tertiary students. Preventive Medicine, 53(4-5), 274-277. doi: 10.1016/j.ypmed.2011.07.017

Samaranayaka, A., & Fletcher, D. (2010). Modelling environmental stochasticity in adult survival for a long-lived species. Ecological Modelling, 221(3), 423-427. doi: 10.1016/j.ecolmodel.2009.10.016

Davie, G., Langley, J., Samaranayaka, A., & Weatherspoon, M. E. (2008). Accuracy of injury coding under ICD-10-AM for New Zealand public hospital discharges. Injury Prevention, 14, 319-323. doi: 10.1136/ip.2007.017954

dos Santos Dias, C. T., Samaranayaka, A., & Manly, B. (2008). On the use of correlated beta random variables with animal population modelling. Ecological Modelling, 215, 293-300.

Samaranayaka, A., Engås, A., & Jørgensen, T. (1997). Effects of hanging ratio and fishing depth on the catch rates of drifting tuna gillnets in Sri Lankan waters. Fisheries Research, 29, 1-12.

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Journal - Research Other

Dovey, S. M., Leitch, S., Wallis, K. A., Eggleton, K. S., Cunningham, W. K., Williamson, M. I., … Tilyard, M. W., Reith, D. M., Samaranayaka, A., & Hall, J. E. (2017). Epidemiology of patient harms in New Zealand: Protocol of a general practice records review study. JMIR Research Protocols, 6(1), e10. doi: 10.2196/resprot.6696

Derrett, S., Harcombe, H., Wyeth, E., Davie, G., Samaranayaka, A., Hansen, P., … Sullivan, T., Wilson, S., & Barson, D. (2017). Subsequent Injury Study (SInS): Improving outcomes for injured New Zealanders. Injury Prevention, 23(6), 429. doi: 10.1136/injuryprev-2016-042193

Tun, T., Nyunt, W. W., Latt, K. Z., Samaranayaka, A., Crump, J. A., Thinn, K. K., Cook, G. M., & Aung, H. L. (2016). Drug-resistant tuberculosis among previously treated patients in Yangon, Myanmar. International Journal of Mycobacteriology, 5(3), 366-367. doi: 10.1016/j.ijmyco.2016.06.004

Cryer, C., Gulliver, P., Langley, J., Davie, G., Samaranayaka, A., & Fowler, C. (2011). A proposed theoretical definition to address the undercounting of injury deaths [Commentary]. Injury Prevention, 17, 219-221. doi: 10.1136/injuryprev-2011-040039

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