Quantifying the magnitude of morbidity and mortality worldwide is difficult, with complicating factors at all levels of care.¹ The most common metric used to quantify the loss of healthy life due to disease is the disability-adjusted life year (DALY),² which is the sum of years of life lost to premature mortality and years of life spent living with morbidity and disability.

The Global Burden of Disease Study (GBD) is a worldwide comprehensive study that examines trends from 1990 to present with annual updates beginning in 2015. In many low-income and middle-income countries, country-specific health data
remain scarce, leading to extrapolation and modeling based on demographics, surveillance systems, household surveys, verbal autopsies, and facility-level data inquiries.^3,4,5,6,7 Caveats aside, the GBD project has documented that cardiovascular diseases are the leading cause of death in almost every region of the world,⁸ accounting for approximately one-third of all deaths globally.⁹ Cardiovascular mortality has increased by 12.5% over the past decade.¹⁰

Noncommunicable diseases in general have shifted to the forefront of the global burden of disease as part of what has been called the “demographic transition”: aging of the global population, improved childhood mortality, and declines in death due to the infectious causes which had previously been at the forefront.¹¹ Between 2005 and 2015, cancer cases increased by 33% and are expected to increase in the future.¹² However, while deaths from noncommunicable disease now account for more than one-half of global health loss,¹³ infectious diseases such as tuberculosis still kill more than 1 million people every year.^11,14 The combination of HIV, tuberculosis, and malaria accounts for approximately 10% of the world’s overall disease burden.

The global burden of disease is not limited to DALYs and mortality rates. The economic burden of diseases is tremendous and is a problem for global economies. The cost of diabetes worldwide has been estimated at $1.31 trillion, or 1.8% of the global gross domestic product in 2015¹⁵ and chronic hepatitis C expenses exceed $10 billion annually in the United States alone.¹⁶

The global burden of surgical disease is substantial but difficult to quantify, particularly in the developing world. Diseases that require surgical and anesthesia care constitute a considerable proportion of the global burden of disease. In 2006, Debas and colleagues estimated the fraction of disease treatable by surgical intervention as 11% of overall disease burden.¹⁷ More recently, Shrime and colleagues, based on survey results, estimated that the burden of disease requiring surgical intervention approximates 30%.¹⁸ Other estimates put the global burden of surgical disease at 30% to 35%^18,19 of the world’s overall disease burden, on par with the disease burden attributable to cardiovascular conditions. Close to 17 million deaths are caused by surgical diseases every year,²⁰ and surgical conditions are estimated to result in losses of 1.25% of the potential GDP each year.²¹ An estimated 12.3 trillion dollars are lost in the GDP of low- and middle-income countries due to surgical conditions.

At least 4.8 billion people do not have access to surgery,²² and despite high surgical rates worldwide, cases are not spread evenly throughout the world. Middle-expenditure and high-expenditure countries, accounting for 30.2% of the world’s population, provided 73.6% of surgeries worldwide in 2004, whereas poor-expenditure countries accounting for 34.8% of the global population yet undertook only 3.5% of all surgical procedures.²³ Greater than 95% of the population of South Asia, central, eastern, and western sub-Saharan Africa do not have access to surgical care, compared to overwhelming access in most regions of the developed world.²² With increasing efforts from institutions such as the Lancet Commission on Global Surgery, launched in 2014, and the World Health Assembly, attention to the global burden of surgical disease has increased in recent years.

The ability to provide surgical care requires an intricate web of factors. Not only are the staff and facilities to perform surgery essential, but demand-side barriers, such as the ability of the population to reach the facility in a timely manner and
to receive surgery without catastrophic expenditure, must also be considered.²² In resource-constrained countries, surgical services are concentrated almost wholly in cities and reserved for those who can pay for them.²⁴ Almost 3.7 billion people, or half of the global population, are at risk of catastrophic expenditure if surgery becomes necessary and 81.3 million people experience financial catastrophe each year.²⁵

The wide scope of surgical needs complicates measurement of the prevalence and the effect of surgical conditions.²⁶ In 2015, the Lancet Commission on Global Surgery found that the consequences of untreated surgical conditions in low- and middle-income countries are large and for many years have gone unrecognized.²⁰ One hundred forty-three million additional surgical procedures are needed each year to save lives and prevent disability.²⁰ Recent efforts to define necessary steps toward global surgery have been taken.^20,27,28

Six core indicators to measure surgical access were outlined by the Lancet Commission on Global Surgery which help set standards for surgical care: geographical accessibility, density of surgical providers, number of procedures performed, perioperative mortality, risk of impoverishing expenditure, and risk of catastrophic expenditure.²⁰ Furthermore, in 2016, researchers proposed three Bellwether procedures, finding that hospitals with the ability to perform caesarean delivery, laparotomy, and treatment of open fracture were more likely to be able to deliver emergency and essential surgical care.²⁷ The Bellwether procedures provide a benchmark to first-level hospitals, anticipating ability to provide essential surgical care.

In the year 2013 it was estimated that 973 million people sustained injuries that warranted health care and that injury accounted for 4.8 million deaths.²⁹ It is estimated that about 16,000 people die from injuries every day. Eighty-five percent of all traumatic injuries occur in developing countries, and worldwide trauma is the leading cause of mortality in the 5 to 40 age group. Even in high-income countries, traumatic unintentional injuries, self-inflicted injuries, and injuries related to interpersonal violence account for the majority of deaths in the 15 to 45 age group.²⁹ The additional burden of the sequelae from trauma with significant morbidities accounts for a very large part of the disability spectrum.

The majority of traumatic deaths are due to road traffic accidents. Traffic accidents are estimated to account for 30% of deaths, globally.²⁹ This number is higher in the low- and middle-income countries with 37% in India as per National Crime Record Bureau report in 2014. A vehicular accident is reported every 2 minutes and a death every 5 minutes on Indian roads.³⁰ In India, the mortality rate for severe injuries (injury severity score of >16) is six times that of developed countries.³⁰

There has been an increase in the incidence of intentional injuries that include self-inflicted and interpersonal violence. Data reported from the United Nations Office on Drugs and Crime suggest while the incidence of homicide is decreasing in Asia and Europe, it is increasing in South America and Eastern and Southern Africa.³¹ Self-harm is the second leading cause of death from injuries, and global trends suggest an uptick, particularly observed during the recent economic global downturn.