Achieving cervical cancer elimination: The simulated impacts of HPV vaccination and transitioning from liquid-based cytology to HPV-based screening test.

The Ministry of Health Malaysia aims to fully replace liquid-based cytology (LBC) with Human Papillomavirus (HPV) tests and increase the screening coverage from a baseline of 25% to 40% by 2023, followed by a 10% yearly increment until 70% coverage. This transition requires proper planning, including the number of tests needed and budget allocation. This study aims to simulate different transition strategies involving the shift from LBC to HPV testing with expanded screening coverage to predict their impact on cervical cancer elimination in Malaysia. A system dynamics model was developed to simulate the transition from LBC to HPV testing and HPV vaccination coverage in Malaysia. The dynamic model utilised local epidemiological data, published research, and expert opinion when data was unavailable. The simulation showed that a combination of high HPV vaccination coverage and transitioning fully to five-yearly HPV testing by 2030, coupled with a 70% screening uptake by 2040, would accelerate cancer elimination in Malaysia by 18 years with an estimated screening cost of MYR1.81 billion equivalent to USD 411 millions compared to the baseline of using LBC as the primary screening method (MYR1.39 billion, USD 315 millions). Sustained, it would lead to averting 6,000 new cancer cases by 2070. Alternatively, conducting HPV screenings twice before age 50 would advance cervical cancer elimination by 14 years and prevent approximately 1000 new cases by 2070, with an estimated cost of MYR1.13 billion equivalent to USD 257 millions. A delay in achieving the full transition prolonged the elimination more than a delay in increasing the screening coverage. In all scenarios, yearly vaccination of 90% of girls age 13 is crucial to achieving elimination. In the Malaysian context, where HPV vaccination coverage has reached considerable levels, the evidence advocates for a full transition from LBC to HPV testing, ideally by 2030. While expanding screening coverage remains a critical factor in this endeavour, the findings unequivocally endorse prioritising the transition process. Trial registration: Trial registration number: NMRR ID-22-00187-DJU.

Combating obesity through healthy eating behavior: a call for system dynamics optimization.

Poor eating behavior has been identified as one of the core contributory factors of the childhood obesity epidemic. The consequences of obesity on numerous aspects of life are thoroughly explored in the existing literature. For instance, evidence shows that obesity is linked to incidences of diseases such as heart disease, type-2 diabetes, and some cancers, as well as psychosocial problems. To respond to the increasing trends in the UK, in 2008 the government set a target to reverse the prevalence of obesity (POB) back to 2000 levels by 2020. This paper will outline the application of system dynamics (SD) optimization to simulate the effect of changes in the eating behavior of British children (aged 2 to 15 years) on weight and obesity. This study also will identify how long it will take to achieve the government's target. This paper proposed a simulation model called Intervention Childhood Obesity Dynamics (ICOD) by focusing the interrelations between various strands of knowledge in one complex human weight regulation system. The model offers distinct insights into the dynamics by capturing the complex interdependencies from the causal loop and feedback structure, with the intention to better understand how eating behaviors influence children's weight, body mass index (BMI), and POB measurement. This study proposed a set of equations that are revised from the original (baseline) equations. The new functions are constructed using a RAMP function of linear decrement in portion size and number of meal variables from 2013 until 2020 in order to achieve the 2020 desired target. Findings from the optimization analysis revealed that the 2020 target won't be achieved until 2026 at the earliest, six years late. Thus, the model suggested that a longer period may be needed to significantly reduce obesity in this population.