P atient safety is a priority in modern health care systems. From 3% to 17% of hospital admissions result in an adverse event,1-8 and almost 50% of these events are considered to be preventable.3,9-12 An adverse event is an unintended injury or complication caused by delivery of clinical care rather than by the patient's condition. The occurrence of adverse events has been well documented; however, identifying modifiable risk factors that contribute to the occurrence of preventable adverse events is critical. Studies of preventable adverse events have focused on many factors, but researchers have only recently begun to evaluate the role of patient characteristics.2,9,12,13 Older patients and those with a greater number of health problems have been shown to be at increased risk for preventable adverse events.10,11 However, previous studies have repeatedly suggested the need to investigate more diverse, modifiable risk factors. 3,6,7,10,11,[14][15][16] Language barriers and disabilities that affect communication have been shown to decrease quality of care;16-20 however, their impact on preventable adverse events needs to be investigated. Patients with physical and sensory disabilities, such as deafness and blindness, have been shown to face considerable barriers when communicating with health care professionals.20-24 Communication disorders are estimated to affect 5%-10% of the general population, 25 and in one study more than 15% of admissions to university hospitals involved patients with 1 or more disabilities severe enough to prevent almost any form of communication.26 In addition, patients with communication disabilities are already at increased risk for depression and other comorbidities.27-29 Determining whether they are at increased risk for preventable adverse events would permit risk stratification at the time of admission and targeted preventive strategies.We sought to estimate the extent to which preventable adverse events that occurred in hospital could be predicted by conditions that affect a patient's ability to communicate. Impact of patient communication problems on the risk of preventable adverse events in acute care settingsBackground: Up to 50% of adverse events that occur in hospitals are preventable. Language barriers and disabilities that affect communication have been shown to decrease quality of care. We sought to assess whether communication problems are associated with an increased risk of preventable adverse events. Methods:We randomly selected 20 general hospitals in the province of Quebec with at least 1500 annual admissions. Of the 145 672 admissions to the selected hospitals in 2000/01, we randomly selected and reviewed 2355 charts of patients aged 18 years or older. Reviewers abstracted patient characteristics, including communication problems, and details of hospital admission, and assessed the cause and preventability of identified adverse events. The primary outcome was adverse events.Results: Of 217 adverse events, 63 (29%) were judged to be preventable, for an overall populat...

A matched case‐control study was undertaken to assess the relative risk associated with known and suspected risk factors of squamous cell carcinoma of the skin among patients in the Montreal region. Three hundred eleven cases histologically diagnosed in 1977 and 1978 in 12 hospitals and meeting strict definition criteria were identified. With the exception of six cases, two controls were matched to each case for sex, age, and hospital of diagnosis. A logistic regression analysis was done. The known host risk factors (eye and hair color, complexion, descent) and nonoccupational sunlight exposure were found to be operative in the Montreal region. After adjusting for these factors, occupational sunlight exposure appeared to be a risk factor. An association was then observed between the risk of squamous cell carcinoma of the skin and tobacco smoking and the use of a sunlamp. Relative risks associated with the above‐mentioned factors were estimated.

To quantify prognosis in patients with end-stage renal disease, we evaluated pretreatment clinical state and ascertained the outcome of all 220 patients who began therapy at two hospitals from 1970 to 1975. Each of three pretreatment characteristics made a statistically significant independent contribution to the relative risk of death: age (relative risk for 10-year increments = 2.2, p less than 0.001); duration of diabetes (relative risk for 10-year increments = 2.2, p less than 0.001); and left-sided heart failure (relative risk = 2.0, p less than 0.001). We combined the effects of these factors in an age-equivalence index that showed a strong gradient in survival rates from lower to higher values; the 5-year survival rate differed between 92% in patients with a score of 30 or less and 6% in patients with a score over 70. This index, which is simple to use, should prove helpful in patient care and can improve the scientific validity of therapeutic comparisons in patients with end-stage renal disease by identifying and adjusting for the selection biases that occur in the allocation of different treatments.

Obesity is a significant risk factor for ATF, and this association may be due to the current "one size fits all" dosing strategy, which warrants further investigation.