Resources Module 1: What is Patient Safety?

Patient story

Betsy A. Lehman was a health columnist with The Boston Globe. She was 39 and since joining the Globe in 1982, her articles had covered medical research to clinical medicine. She was a happily married mother of two daughters aged 7 and 3 years. When she learned that she had advanced stage breast cancer, she chose the Dana-Farber Cancer Institute, a prestigious hospital affiliated with Harvard Medical School. It was decided by her oncologist to give her the chemotherapeutic drug cyclophosphamide, or Cytoxan, for 4 days. During this time, she progressively felt unwell, which she reported to her treating physicians. On December 3, 1994, the day she was looking forward to seeing her daughters and go home, she died. The following February while doing a routine review of her case, two clerks found a mathematical error in the dose of Cytoxan which lead to her death.  The amount was supposed to be calculated according to the amount of her body surface area. The correct dosage would have been 1,630 milligrams each day for four consecutive days. Instead she received 6,520 milligrams a day for four days, four times the intended dose. The medication order was written by a physician who misunderstood the study protocol countersigned by five other doctors and nurses. Even the pharmacists did not pick up the error leading to the fatal mistake (Altman 1995).

What is Patient Safety

The concept of “Patient Safety” aims to prevent such dreadful medical errors from happening.  WHO defines patient safety as “the reduction of risk of unnecessary harm associated with health care to an acceptable minimum”.  It is estimated that about 10% of hospital patients suffer an adverse event, more in developing countries.  Patient safety is an issue for all countries and all health care delivery services, whether privately or government-funded. In developing countries, the poor state of infrastructure and equipment, unreliable supply and quality of drugs, shortcomings in infection control and waste management, poor performance of personnel, low motivation or insufficient skills and severe under-financing of health services adds to the risk. Health-care providers can improve patient safety by engaging with patients, checking procedures, learning from errors and communicating effectively within the health-care team. If we blame individual practitioners for adverse events, we will not be able to learn from them and improve.  Such a "blame culture" runs counter to learning and continuous improvements in patient safety - a lesson we have learnt from other complex safety-critical industries such as aviation and nuclear power plants where safety frameworks were developed to reduce system errors.  Read more using World Health Organization’s handout on “What is Patient Safety?” here

To properly comprehend the concept of “Patient Safety”, it is important to understand the key terms. Please read and refer during this course to the World Health Organization’s handout on “Patient Safety Definitions” here.

Additional recommended reading for this course includes the book, “Safer Healthcare: Strategies for the Real World” by Charles Vincent and Rene Amalberti. This book is free to download as it is open access.

Another very useful resource is A Guide to Patient Safety Improvement, Canadian Patient Safety Institute. 


Altman, L (1995). Big doses of chemotherapy drug killed patient, hurt 2d.The New York Times [Online][Accessed on 28 April 2021][

Vincent, C & Amalberti, R (2016). Safer Healthcare - Strategies for the Real World.  [Online ][Accessed on 28 April 2021] [Available at]

World Health Organization (WHO) (2012). What is Patient Safety? [Online][Accessed on 28 April 2021[Available at]

World Health Organization (WHO) (2012). Definitions of Key Concepts from the WHO Patient Safety Curriculum Guide, 2011 [Online][Accessed on 28 April 2021][Available at]

Last modified: Tuesday, 8 June 2021, 6:42 AM