Updated October 2026.
Ask any nurse what makes a shift unsafe and the answer is usually the same: too many patients for one nurse. The nurse-to-patient ratio is the number of patients a single nurse cares for at one time. It’s one of the strongest predictors of how safe a hospital is.
What the evidence says
The best-known study, by Linda Aiken and colleagues in JAMA in 2002, looked at surgical patients in Pennsylvania hospitals. It found that each extra patient added to a nurse’s workload was linked to about a 7% higher chance of a patient dying within 30 days of admission. Heavier workloads were also tied to more nurse burnout and job dissatisfaction. Many studies since, across different countries, have found the same pattern: when nurses are stretched too thin, complications are missed and patients suffer.
Understaffing doesn’t just harm patients. It drives nurses out of the profession, which makes staffing even worse.
How safe-staffing rules work
Some places set minimum staffing levels in law. California was the first US state to do so, with fixed maximums by unit: for example, no more than five patients per nurse on medical-surgical wards, and far fewer in intensive care. Other systems, including several in Australia and the UK, use legal ratios or staffing tools that match nurse numbers to how sick patients are.
The right ratio depends on the setting. Critically ill patients may need one nurse each, while stable ward patients can safely be shared among more. What matters is that staffing matches patient need, not the budget alone.
The global picture
The World Health Organization’s State of the World’s Nursing 2025 report counted about 29.8 million nurses worldwide in 2023, with a shortage of around 5.8 million. The gap is expected to narrow to about 4.1 million by 2030, but WHO warns that nurse density in the African region will see little or no growth.
Where Nigeria stands
Nigeria had about 326,000 nurses and midwives at the end of 2020, roughly a fifth of all nurses and midwives in the WHO African region, according to WHO’s African health observatory. But for a population of over 200 million, that is far too few, and the gap has widened as thousands of nurses have moved abroad. Across the African region there were about 18 nurses and midwives per 10,000 people in 2020, and the region had only an estimated 39% of the nurses and midwives it needed.
On Nigerian wards, it’s common for one nurse to cover a whole ward on a night shift. Nigeria has no legally enforced nurse-to-patient ratio.
What would help
- Recruit and retain nurses, with better pay, safer working conditions and career paths that give nurses a reason to stay.
- Set national staffing standards by ward type, and monitor them.
- Use acuity tools that match staffing to how sick patients are.
- Protect nurses who report unsafe staffing. Raising concerns is part of patient safety, not disloyalty.
For nurses on an understaffed shift: prioritise using clinical judgement, document your workload and any care you couldn’t safely deliver, escalate to your nurse in charge in writing, and keep patients informed. Your notes protect both your patients and you.
Read also: UNILORIN urges new nurses to stay · Patients’ Bill of Rights in Nigeria
Sources: Aiken LH et al., “Hospital nurse staffing and patient mortality, nurse burnout, and job dissatisfaction”, JAMA, 2002; Becker’s: WHO State of the World’s Nursing 2025; WHO African Health Observatory: nursing and midwifery workforce fact sheet.