Sains Malaysiana 51(5)(2022): 1599-1608

http://doi.org/10.17576/jsm-2022-5105-27

Insights into Variations in COVID-19 Infections in Malaysia

(Pandangan tentang Variasi dalam Jangkitan COVID-19 di Malaysia)

KIRUBHA A/P SANMUGAN & MUZALWANA ABDUL TALIB^*

Department of Economics and Applied Statistics, Faculty of Business and Economics, Universiti Malaya, 50603 Kuala Lumpur, Federal Territory, Malaysia

Received: 28 July 2021/Accepted: 21 March 2022

Abstract

The present study aims to visualize the variations in the number of confirmed daily COVID-19 infections during the third wave in Malaysia through the application of control charts. This study also attempts to propose the target number of daily new cases that would bring the pandemic situation in Malaysia under control by utilizing the confirmed daily cases in Malaysia starting from 8^th September 2020 until 30^th June 2021. A modified Shewhart control chart was adopted to monitor the variations before and after the commencement of National Immunisation Programme (NIP). The chart shows a declining trend in the number of cases after the rollout of NIP whereby several days were brought to a state of statistical-in-control. But in less than three months after NIP commencement, there were huge variations in COVID-19 cases leading to drastic increase in the mean number of cases. These signal the presence of unnatural or assignable causes of variations which could be attributed to failure of curbing the risks of transmission, existence of various variants in the community, easing of containment measures and less adherence to the COVID-19 Standard Operating Procedures (SOPs). Significant shifts in the mean values prompt the development of a 3-phase modified Shewhart control chart. From the 3-phase chart, a series of daily number new cases that can be set as the target value to bring the pandemic situation in Malaysia under control, while flattening the epidemiological curve in the very near term.

Keywords: Control charts; COVID-19; variation study

ABSTRAK

Kajian ini bertujuan untuk menggambarkan variasi dalam jumlah jangkitan COVID-19 harian yang disahkan semasa gelombang ketiga pandemik ini di Malaysia melalui penggunaan carta kawalan. Dengan menggunakan kes harian bermula 8 September 2020 sehingga 30 Jun 2021, kajian juga cuba mencadangkan sasaran bilangan kes baru harian yang mungkin dapat membawa kepada keadaan pandemik yang lebih terkawal di Malaysia. Kajian ini mengadaptasi carta kawalan Shewhart yang diubah suai untuk memantau variasi bilangan kes sebelum dan selepas bermulanya Program Imunisasi Kebangsaan (NIP). Carta dihasilkan menunjukkan trend penurunan bilangan kes selepas pelancaran NIP dengan beberapa hari telah dikesan berada pada keadaan statistik-dalam-kawalan. Pun begitu, dalam masa kurang daripada tiga bulan selepas NIP dilancarkan, didapati terdapat variasi yang besar dalam kes COVID-19 yang menyebabkan peningkatan drastik dalam purata bilangan kes. Ini memberi isyarat hadirnya punca variasi luar biasa yang boleh dikaitkan dengan kegagalan membendung risiko penularan, kewujudan pelbagai varian baru dalam komuniti, pelonggaran langkah membendung serta kurangnya pematuhan kepada Prosedur Operasi Piawai (SOP) COVID-19. Anjakan ketara dalam nilai purata telah mendorong kepada pembangunan carta kawalan Shewhart ubah suai 3 fasa. Hasil daripada carta ini digunakan untuk membuat beberapa saranan mengenai bilangan kes baru harian yang boleh dijadikan sebagai sasaran dalam usaha membawa keadaan pandemik di Malaysia yang lebih terkawal, di samping usaha melandaikan lengkungan epidemiologi untuk tempoh terdekat ini.

Kata kunci: Carta kawalan; COVID-19; kajian varians

REFERENCES

Ain Umaira Md Shah, Syafiqah Nur Azrie Safri, Rathedevi Thevadas, Nor Kamariah Noordin, Azmawani Abd Rahman, Zamberi Sekawi, Aini Ideris, & Mohamed Thariq Hameed Sultan 2020. COVID-19 outbreak in Malaysia: Actions taken by the Malaysian government. International Journal of Infectious Diseases 97: 108-116.

Ansah, J.P., Matchar, D.B., Shao-Wei, S.L., Low, J.G., Pourghaderi, A.R., Siddiqui, F.J., Tessa Lui, S.M., Aloysius Chia, W-Y. & Marcus Eng, H.O. 2021. The effectiveness of public health interventions against COVID-19: Lessons from the Singapore experience. PLoS ONE. https://doi.org/10.1371/journal.pone.0248742.

Arantes, A., Carvalho, E.D., Medeiros, E.A., Farhat, C.K. & Mantese, O.C. 2003. Use of statistical process control charts in the epidemiological surveillance of nosocomial infections. Rev. Saude Publica 37: 768-774.

Benneyan, J.C., Lloyd, R.C. & Plesk, P.E. 2003. Statistical process control as a tool for research and healthcare improvement. Quality Safety Health Care 12: 458-464.

Berwick, D.M. 1989. Continuous improvement as an ideal in health care. The New England Journal of Medicine 320(1): 53-56.

Centers for Disease Control and Prevention (CDC). 2021. COVID-19 Science Update. https://www.cdc.gov/library/covid19/scienceupdates.html?Sort=Date%3A%3Adesc.

Charumilind, S., Craven, M., Lamb, J., Sabow, A. & Wilson, M. 2021. When Will the COVID-19 Pandemic End? McKinsey & Company. https://www.mckinsey.com/industries/healthcare-systems-and-services/our-insights/when-will-the-covid-19-pandemic-end#.

Chen, L.W. & Yeo, T.L. 2021. Covid-19 Response: FAQs (MCO 2021). Knowledge Highlights. Rahmat Lim & Partners https://www.rahmatlim.com/perspectives/articles/17541/mykh-covid-19-response-faqs-mco-2021.

Clemente, F., Papi, M., Pontecorvi, L. & Menichetti, A. 2016. Evaluation of indices for the measurement of quality in health systems. International Journal of Metrology and Quality Engineering 7(4): 405.

Crisis Preparedness and Response Centre (CPRC). 2021. Current Situation of COVID-19 Pandemic in Malaysia. Ministry of Health Malaysia. http://covid-19.moh.gov.my/.

Das, N. 2003. Study on implementing control chart assuming negative binomial distribution with varying sample size in a software industry. Software Quality Professional Magazine. ASQ. http://rube.asq.org/pub/sqp/past/vol6_issue1/das.html

Elengoe, A. 2020. COVID-19 outbreak in Malaysia. Osong Public Health and Research
Perspectives 11(3): 93-100. https://doi.org/10.24171/j.phrp.2020.11.3.08

Gomes, I.C., Mingoti, S.A. & Oliveira, C.D. 2011. A novel experience in the use of control charts for the detection of nosocomial infection outbreaks. Clinics 66: 1681-1689.

Hawkins, D.M. & Zamba, K.D. 2003. On small shifts in quality control. Quality Engineering, 16(1): 143-149. https://doi.org/10.1081/QEN-120020780

Hoerl, R. & Snee, R. 2012. Statistical Thinking: Improving Business Performance. 2nd ed. New York: John Wiley & Sons, Inc.

Idrus, P.G. 2021. Southeast Asian nations race to acquire COVID-19 vaccine. Anadolu Agency. https://www.aa.com.tr/en/asia-pacific/southeast-asian-nations-race-to-acquire-covid-19-vaccine/2102821#. Accessed on 2 June 2021.

Inkelas, M., Blair, C., Furukawa, D., Manuel, V.G., Malenfant, J.H., Martin, E., Emeruwa, I., Kuo, T., Arangua, L., Robles, B. & Provost, L.P. 2021. Using control charts to understand community variation in COVID-19. PLoS ONE 16(4): e0248500.

Kenkel, J.L. 1989. Introductory Statistics for Management and Economics. 3rd ed. Pws Pub Co.

Levine, D.M., Stephan, D.F. & Szabat, K.A. 2018. Statistics for Managers Using Microsoft Excel. Global Edition. 8th ed., Pearson Education Limited.

Montgomery, D.C. 2019. Introduction to Statistical Quality Control. 8th edition. New York: John Wiley & Sons Inc.

Mohammed, M.A., Cheng, K.K., Rouse, A. & Marshall, T. 2001. Bristol, shipman, and clinical governance: Shewhart’s forgotten lessons. The Lancet 735: 463-467.

Perla, R.C., Provost, S.M., Parry, G.J., Little, K. & Provost, L.P. 2020. Understanding variation in reported COVID-19 deaths with a novel Shewhart chart application. International Journal for Quality in Health Care 33(1): mzaa069.

Phillips, N. 2021. The coronavirus is here to stay - here’s what that means. Nature 590: 382-384.

Rampal, L. 2020. COVID-19 pandemic update. The Medical Journal of Malaysia 75(3): 195-198.

Rampal, L. & Liew, B.S. 2021. Malaysia's third COVID-19 wave - a paradigm shift required. Med. J. Malaysia 76(1): 1-4.

Rampal, L. & Seng, L.B. 2020. Coronavirus disease (COVID-19) pandemic. The Medical Journal of Malaysia 75(2): 95-97.

Reporting Asean (2021). IN NUMBERS: COVID-19 Vaccination in Southeast Asia, Reporting ASEAN. https://www.reportingasean.net/in-numbers-covid-19-vaccination-in-southeast-asia/

Suman, G. & Prajapati, D. 2018. Control chart applications in healthcare: A literature review. International Journal of Metrology and Quality Engineering 9: 5.

The Edge Markets. 2021. COVID-19 Vaccination Tracker. Ministry of Health Malaysia. https://www.theedgemarkets.com/article/vaccination-tracker.

von Hippel, P.T. 2005.  Mean, median, and skew: Correcting a textbook rule. Journal of Statistics Education 13: 2. DOI: 10.1080/10691898.2005.11910556

World Health Organization. 2020(a). February 12. https://www.who.int/publications/m/item/covid-19-public-health-emergency-of-international-concern-(pheic)-global-research-and-innovation-forum.

World Health Organization. 2020(b). March 11. https://www.who.int/director-general/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020.

World Health Organization. March 27. 2020(c). Modes of Transmission of Virus Causing COVID-19: Implications for IPC Precaution Recommendations. Scientific brief https://www.who.int/news-room/commentaries/detail/modes-of-transmission-of-virus-causing-covid-19-implications-for-ipc-precaution-recommendations

World Health Organization. 2021. July 3. https://covid19.who.int/.

^*Corresponding author; email: wana_am@um.edu.my