In poor countries, there are often failures in support systems intended to ensure the availability of oxygen, blood transfusions and postoperative antibiotics, and sometimes even just clean operating rooms.

When checklists are strictly adhered to, missing even one of those elements can prevent the operation from beginning. Instead, some hospitals just avoid the checklist.

There is enormous room for improvement, the study found.

For example, up to 95 percent of Africa’s population does not have access to safe and affordable surgery, and African patients are twice as likely to die after an operation, compared with the global average, said Dr. Bruce M. Biccard, an anesthesiologist at the University of Cape Town and a leader of the African Surgical Outcomes Study, which produced some of the data used in the new report.

In countries where doctors and nurses do not speak one of the six official languages of the United Nations — Arabic, Chinese, English, French, Russian or Spanish — a checklist is less likely to be used. Also, cultural barriers have hindered its adoption.

The checklist includes requirements that doctors and nurses introduce themselves and confirm that all have the same understanding of how the operation will ideally proceed. But teamwork can be difficult to introduce, both in traditional cultures based on hierarchy and obedience and in intensely competitive environments like those in American medical schools.

Even hospitals that faithfully used a checklist often adapted it to local circumstances, the report found. Some translated it into Tagalog and Amharic, for example. A West African surgical team added a requirement that the hospital’s generator be working. A Guatemalan team added pain-control medication to the list of requirements.