Attività

When her Danish colleagues first suggested distributing protective cloth face masks to people in Guinea-Bissau to stem the spread of the coronavirus, Christine Benn wasn’t so sure.

“I said, ‘Yeah, that might be good, but there’s limited data on whether face masks are actually effective,’” says Benn, a global-health researcher at the University of Southern Denmark in Copenhagen, who for decades has co-led public-health campaigns in the West African country, one of the world’s poorest.

That was in March. But by July, Benn and her team had worked out how to possibly provide some needed data on masks, and hopefully help people in Guinea-Bissau. They distributed thousands of locally produced cloth face coverings to people as part of a randomized controlled trial that might be the world’s largest test of masks’ effectiveness against the spread of COVID-19.

Face masks are the ubiquitous symbol of a pandemic that has sickened 35 million people and killed more than 1 million. In hospitals and other health-care facilities, the use of medical-grade masks clearly cuts down transmission of the SARS-CoV-2 virus. But for the variety of masks in use by the public, the data are messy, disparate and often hastily assembled. Add to that a divisive political discourse that included a US president disparaging their use, just days before being diagnosed with COVID-19 himself. “People looking at the evidence are understanding it differently,” says Baruch Fischhoff, a psychologist at Carnegie Mellon University in Pittsburgh, Pennsylvania, who specializes in public policy. “It’s legitimately confusing.”

To be clear, the science supports using masks, with recent studies suggesting that they could save lives in different ways: research shows that they cut down the chances of both transmitting and catching the coronavirus, and some studies hint that masks might reduce the severity of infection if people do contract the disease.

But being more definitive about how well they work or when to use them gets complicated. There are many types of mask, worn in a variety of environments. There are questions about people’s willingness to wear them, or wear them properly. Even the question of what kinds of study would provide definitive proof that they work is hard to answer.

“How good does the evidence need to be?” asks Fischhoff. “It’s a vital question.”

The microchip also is embedded with flexible electronics connected to the sensor, enabling data to be transmitted wirelessly to the app for on-site assessment and analysis in real-time. Data is sent to the patient's paired mobile device, on which it is stored and analysed. This processor also is powered by a rechargeable battery. In the study, we used disposable infusion needles with a new type separation-free safety tube for the patients in the intervention group and conventional ones with a self-contained protective cover in the control group. Patients in both groups volunteered to participate and had signed informed consent.

Operation Methods

Six ward nurses with proficiency in the conventional infusion operation were selected, including 2 nurses working for 1-3 years, 2 for 3-5 years, and 2 for over 5 years. Before the project, all of them were trained in the operation of this new type safety tube and qualified. In the control group, conventional disposable infusion needles were used. After breathing, the self-contained protective cover was discarded, and the needle was fixed after acupuncture, then separated from the infusion set into a sharps box at the end. Patients in the intervention group were treated with new disposable infusion sets. The specific operation steps were as follows: (1) Instead of being removed after breathing, the safety tube slid to the flexible tube when the fin of the needle was pushed along the slit to make the needle out of the tube. Then, the infusion operation was as the same as the control group. (2) After infusion, the needle was removed. The upper end of the flexible tube away from the needle was raised, and the needle side was lowered to make the safety tube slide down to the needle side. Then, the fin was pushed to slide along the slit into the rectangular hole. The needle was thus blocked, and the whole infusion set was disposed into a special collection bag.