This work presents a statistical regression-based sensitivity analysis to extract interpretable analytical relationships between epidemiological parameters. Unlike previous studies that relied on numerical simulation of the SIR model, this provides a streamlined predictive framework for decision making and rapid evaluation. Mathematical models help us to study the transmission of infectious diseases and evaluate the effectiveness of public health strategies. Here, we emphasize the sensitivity of the Susceptible–Infected–Recovered (SIR) model. A linear regression equation is introduced to facilitate an analysis of the transmission of COVID-19 in Iraq. The model is modified with 2020 data provided by the Iraqi Ministry of Health, which corresponds to the first wave of the pandemic. The estimated value of the basic reproduction number (R_0) is about 2.5 which explains the fast exponential rise in infection numbers at this period. There is an inverse linear connection between the rate of recovery (γ) and the duration of the epidemic (t ̂_d) given by t ̂_d = -432.87γ + 259.75. The findings show that improved recovery processes also reduce the epidemic period. Furthermore, increasing the transmission coefficient (β) results in an infection peak more quickly, as indicated by T ̂_peak = -163.36β + 93.54. These results are important for improving epidemiological modeling and helping decision makers make important decisions about future disease outbreaks.
Keywords
COVID-19IraqRegressionSensitivity AnalysisSIR
References
X. Li et al., “Evolutionary history, potential intermediate animal host, and cross-species analyses of SARS-CoV-2,” J. Med. Virol., vol. 92, no. 6, pp. 602-611, Jun. 2020, [Online]. Available: https://doi.org/10.1002/jmv.25731.
A. Msmali, M. Zico, I. Mechai, and A. Ahmadini, “Modeling and simulation: A study on predicting the outbreak of COVID-19 in Saudi Arabia,” Discrete Dyn. Nat. Soc., vol. 2021, no. 1, Art. no. 5522928, 2021, [Online]. Available: https://doi.org/10.1155/2021/5522928.
B. Tang et al., “Estimation of the transmission risk of the 2019-nCoV and its implication for public health interventions,” J. Clin. Med., vol. 9, no. 2, Art. no. 462, Feb. 2020, [Online]. Available: https://doi.org/10.3390/jcm9020462.
S. Misra, “Mathematical modeling of infectious disease spread using the SIR model,” Biomed. Res., Nov. 2024, [Online]. Available: https://biomedres.us/fulltexts/BJSTR.MS.ID.009302.php.
E. Bontempi and M. Coccia, “International trade as critical parameter of COVID-19 spread that outclasses demographic, economic, environmental, and pollution factors,” Environ. Res., vol. 201, Art. no. 111514, Sep. 2021, [Online]. Available: https://doi.org/10.1016/j.envres.2021.111514.
E. Bontempi, “Commercial exchanges instead of air pollution as possible origin of COVID-19 initial diffusion phase in Italy: More efforts are necessary to address interdisciplinary research,” Environ. Res., vol. 188, Art. no. 109775, Oct. 2020, [Online]. Available: https://doi.org/10.1016/j.envres.2020.109775.
E. Bontempi, M. Coccia, S. Vergalli, and A. Zanoletti, “Can commercial trade represent the main indicator of the COVID-19 diffusion due to human-to-human interactions? A comparative analysis between Italy, France, and Spain,” Environ. Res., vol. 201, Art. no. 111529, 2021, [Online]. Available: https://doi.org/10.1016/j.envres.2021.111529.
U. Anand et al., “Novel coronavirus disease 2019 (COVID-19) pandemic: From transmission to control with an interdisciplinary vision,” Environ. Res., vol. 197, Art. no. 111126, 2021, [Online]. Available: https://doi.org/10.1016/j.envres.2021.111126.
E. Bontempi, S. Vergalli, and F. Squazzoni, “Understanding COVID-19 diffusion requires an interdisciplinary, multi-dimensional approach,” Environ. Res., vol. 188, Art. no. 109814, 2020, [Online]. Available: https://doi.org/10.1016/j.envres.2020.109814.
K. Al Huraimel, M. Alhosani, S. Kunhabdulla, and M. H. Stietiya, “SARS-CoV-2 in the environment: Modes of transmission, early detection and potential role of pollutions,” Sci. Total Environ., vol. 744, Art. no. 140946, 2020, [Online]. Available: https://doi.org/10.1016/j.scitotenv.2020.140946.
J. Yuan, M. Li, G. Lv, and Z. K. Lu, “Monitoring transmissibility and mortality of COVID-19 in Europe,” Int. J. Infect. Dis., vol. 95, pp. 311-315, 2020, [Online]. Available: https://doi.org/10.1016/j.ijid.2020.03.050.
Y. Liu, A. A. Gayle, A. Wilder-Smith, and J. Rocklöv, “The reproductive number of COVID-19 is higher compared to SARS coronavirus,” J. Travel Med., vol. 27, no. 2, pp. 1-4, Mar. 2020, [Online]. Available: https://doi.org/10.1093/jtm/taaa021.
D. K. Rosario, Y. S. Mutz, P. C. Bernardes, and C. A. Conte Junior, “Relationship between COVID-19 and weather: Case study in a tropical country,” Int. J. Hyg. Environ. Health, vol. 229, Art. no. 113587, 2020, [Online]. Available: https://doi.org/10.1016/j.ijheh.2020.113587.
C. Ma et al., “Understanding dynamics of pandemic models to support predictions of COVID-19 transmission: Parameter sensitivity analysis of SIR type models,” IEEE J. Biomed. Health Inform., vol. 26, no. 6, pp. 2458-2468, Jun. 2022, [Online]. Available: https://doi.org/10.1109/JBHI.2022.3168825.
A. Lawan, A. Salihu, I. Ahmad, J. Abdullahi, and U. Abdullahi, “Qualitative and sensitivity analysis on simple epidemic model (SIR-model): Ensuring well-posedness and stability,” J. Stat. Sci. Comput. Intell., vol. 1, no. 4, pp. 312-320, 2025, [Online]. Available: https://doi.org/10.64497/jssci.49.
S. Abolmaali and S. Shirzaei, “A comparative study of SIR model, linear regression, logistic function, and ARIMA model for forecasting COVID-19 cases,” AIMS Public Health, vol. 8, no. 4, p. 598, 2021, [Online]. Available: https://doi.org/10.3934/publichealth.2021048.
H. H. Weiss, “The SIR model and the foundations of public health,” Mater. Mat., no. 3, pp. 1-17, 2013.
B. Palmieri and M. Vadala, “Oral THC: CBD cannabis extract in main symptoms of Alzheimer disease: Agitation and weight loss,” Clin. Ter., vol. 174, no. 1, pp. 53-60, 2023, [Online]. Available: https://doi.org/10.7417/CT.2023.2497.
C. Gouriéroux and Y. Lu, “Susceptible-infected-recovered model with stochastic transmission,” Can. J. Stat., vol. 53, no. 2, p. e11835, 2025, [Online]. Available: https://doi.org/10.1002/cjs.11835.
T. Sudhakar, A. Bhansali, J. Walkington, and D. Puelz, “The disutility of compartmental model forecasts during the COVID-19 pandemic,” Front. Epidemiol., vol. 4, Art. no. 1389617, 2024, [Online]. Available: https://doi.org/10.3389/fepid.2024.1389617.
S. Rana, “Bridging mechanistic and data-driven models: A novel framework for epidemic forecasting,” J. Appl. Stat.: Environ. Stat. Data Sci., vol. 1, no. 1-4, pp. 5-18, 2025, [Online]. Available: https://doi.org/10.1080/29984688.2025.2511594.