Changing experience of adverse medical events in the National Health Service: Comparison of two population surveys in 2001 and 2013.

Care quality is important to patients and providers, but is hard to measure. This study aimed to examine changes in the frequency and severity of one quality measure - adverse events associated with medical care - in Great Britain over a 12-year period when available resources initially expanded and were subsequently constrained. Data on perceived adverse events, collected from two representative population surveys in 2001 and 2013, were analysed and compared. The samples consisted of 8202 adults aged 15 and over in 2001 and 19,746 adults aged 15 and over in 2013. The main outcome measures were self-reported illness, injury or impairment caused in the opinion of the respondent by medical treatment or care. Respondents were also asked about the perceived severity of harm in terms of health and work, and any actions taken in response. The proportion of all respondents reporting that over the last three years they had suffered some illness, injury or impairment that in their opinion was caused by their medical treatment or care was 2.5% (497/19746) in 2013, compared with 4.8% (391/8202) in 2001, a reduction of 33% after adjusting for age, gender, income and social class differences between the two surveys. Perceived impact on health and work of these events was similar in both surveys, as was the proportion of injured respondents who pursued a legal claim for financial compensation, at 11% (53/497) in 2013 and 10.5% (41/391) in 2001. We also report multivariate analyses of perceived harm rates and severity, and propensity to seek, and accept, compensation. Our results suggest that the NHS became significantly safer over this period when measured by patient perceived harm from medical care. Our survey method could provide a valuable contribution to the monitoring of trends in health-care related adverse events and the impact of patient safety initiatives.