The impact of behavioural risk factors on communicable diseases: a systematic review of reviews

Abstract

Background The coronavirus (COVID-19) pandemic has highlighted that individuals with behavioural risk factors commonly associated with non-communicable diseases (NCDs), such as smoking, harmful alcohol use, obesity, and physical inactivity, are more likely to experience severe symptoms from COVID-19. These risk factors have been shown to increase the risk of NCDs, but less is known about their broader influence on communicable diseases. Taking a wide focus on a range of common communicable diseases, this review aimed to synthesise research examining the impact of behavioural risk factors commonly associated with NCDs on risks of contracting, or having more severe outcomes from, communicable diseases. Methods Literature searches identified systematic reviews and meta-analyses that examined the association between behavioural risk factors (alcohol, smoking, illicit drug use, physical inactivity, obesity and poor diet) and the contraction/severity of common communicable diseases, including infection or associated pathogens. An a priori, prospectively registered protocol was followed (PROSPERO; registration number CRD42020223890). Results Fifty-three systematic reviews were included, of which 36 were also meta-analyses. Reviews focused on: tuberculosis, human immunodeficiency virus, hepatitis C virus, hepatitis B virus, invasive bacterial diseases, pneumonia, influenza, and COVID-19. Twenty-one reviews examined the association between behavioural risk factors and communicable disease contraction and 35 examined their association with communicable disease outcomes (three examined their association with both contraction and outcomes). Fifty out of 53 reviews (94%) concluded that at least one of the behavioural risk factors studied increased the risk of contracting or experiencing worse health outcomes from a communicable disease. Across all reviews, effect sizes, where calculated, ranged from 0.83 to 8.22. Conclusions Behavioural risk factors play a significant role in the risk of contracting and experiencing more severe outcomes from communicable diseases. Prevention of communicable diseases is likely to be most successful if it involves the prevention of behavioural risk factors commonly associated with NCDs. These findings are important for understanding risks associated with communicable disease, and timely, given the COVID-19 pandemic and the need for improvements in future pandemic preparedness. Addressing behavioural risk factors should be an important part of work to build resilience against any emerging and future epidemics and pandemics.

Syndromic surveillance of respiratory-tract infections and hand hygiene practice among pilgrims attended Hajj in 2021: a cohort study

“…Obesity was identified to be a significant risk factor in this study, and obese pilgrims had a more than four-fold increased risk of RTIs. Review studies that explored the relationship between obesity and viral RTIs concluded that obesity raises the risk of contracting and having severe complications from ILI and COVID-19 [ 25 – 27 ]. Another study that investigated the correlation between the prevalence of obesity and COVID-19 infection rate in 54 countries detected that the residents of Saudi Arabia have the highest prevalence of obesity of 35% and it was significantly associated with the susceptibility to COVID-19 [ 28 ].…”

“…Furthermore, according to the rules of ‘Ihram’, scented toiletries including scented soaps, perfumes, or deodorant on pilgrim’s body or clothing are avoided. The religious and cultural preference of Muslims to avoid products that contain alcohol when alternatives are available may further explain the low compliance of using alcohol-based hand sanitiser among Hajj pilgrims [ 27 ]. Unlike the reported barrier in our 2019 Hajj study [ 7 ], the unavailability of soap and hand sanitisers was not a major hindrance for pilgrims who attended this Hajj to clean their hands, and this was possibly due to the distribution of a large volume of hygienic products at every Hajj sites.…”

“…Obesity was identified to be a significant risk factor in this study, and obese pilgrims had a more than four-fold increased risk of RTIs. Review studies that explored the relationship between obesity and viral RTIs concluded that obesity raises the risk of contracting and having severe complications from ILI and COVID-19 [25][26][27].…”

Syndromic surveillance of respiratory-tract infections and hand hygiene practice among pilgrims attended Hajj in 2021: A cohort study

“…Obesity was identi ed to be a signi cant risk factor in this study, and obese pilgrims had a more than four-fold increased risk of RTIs. Review studies that explored the relationship between obesity and viral RTIs concluded that obesity raises the risk of contracting and having severe complications from ILI and COVID-19 [22][23][24]. Another study that investigated the correlation between the prevalence of obesity and COVID-19 infection rate in 54 countries detected that the residents of Saudi Arabia have the highest prevalence of obesity of 35% and it was signi cantly associated with the susceptibility to COVID-19 [25].…”

Impact of ultra-processed food intake on the risk of COVID-19: a prospective cohort study

“…Although socioeconomic characteristics, lifestyle factors, poor metabolic health, and preexisting chronic conditions were suggested to be risk factors for COVID-19, the whole impactors are still elusive [4][5][6]. While vaccines, effective treatments, and mitigation measures have been launched to deal with COVID-19, understanding the risk factors of COVID-19 would be of great importance in building up people's health and preventing acute infectious disease in the future [7].…”