Adverse drug reaction

About: Adverse drug reaction is a research topic. Over the lifetime, 4450 publications have been published within this topic receiving 95689 citations. The topic is also known as: ADR & Adverse reaction to drug.

A method for estimating the probability of adverse drug reactions

Abstract: The estimation of the probability that a drug caused an adverse clinical event is usually based on clinical judgment. Lack of a method for establishing causality generates large between-raters and within-raters variability in assessment. Using the conventional categories and definitions of definite, probable, possible, and doubtful adverse drug reactions (ADRs), the between-raters agreement of two physicians and four pharmacists who independently assessed 63 randomly selected alleged ADRs was 38% to 63%, kappa (k, a chance-corrected index of agreement) varied from 0.21 to 0.40, and the intraclass correlation coefficient of reliability (R[est]) was 0.49. Six (testing) and 22 wk (retesting) later the same observers independently reanalyzed the 63 cases by assigning a weighted score (ADR probability scale) to each of the components that must be considered in establishing causal associations between drug(s) and adverse events (e.g., temporal sequence). The cases were randomized to minimize the influence of learning. The event was assigned a probability category from the total score. The between-raters reliability (range: percent agreement = 83% to 92%; κ = 0.69 to 0.86; r = 0.91 to 0.95; R(est) = 0.92) and within-raters reliability (range: percent agreement = 80% to 97%; κ = 0.64 to 0.95; r = 0.91 to 0.98) improved (p < 0.001). The between-raters reliability was maintained on retesting (range: r = 0.84 to 0.94; R(est) = 0.87). The between-raters reliability of three attending physicians who independently assessed 28 other prospectively collected cases of alleged ADRs was very high (range: r = 0.76 to 0.87; R(est) = 0.80). It was also shown that the ADR probability scale has consensual, content, and concurrent validity. This systematic method offers a sensitive way to monitor ADRs and may be applicable to postmarketing drug surveillance. Clinical Pharmacology and Therapeutics (1981) 30, 239–245; doi:10.1038/clpt.1981.154

Use of proportional reporting ratios (PRRs) for signal generation from spontaneous adverse drug reaction reports

Abstract: BACKGROUND: The process of generating 'signals' of possible unrecognized hazards from spontaneous adverse drug reaction reporting data has been likened to looking for a needle in a haystack. However, statistical approaches to the data have been under-utilised. METHODS: Using the UK Yellow Card database, we have developed and evaluated a statistical aid to signal generation called a Proportional Reporting Ratio (PRR). The proportion of all reactions to a drug which are for a particular medical condition of interest is compared to the same proportion for all drugs in the database, in a 2 x 2 table. We investigated a group of newly-marketed drugs using as minimum criteria for a signal, 3 or more cases, PRR at least 2, chi-squared of at least 4. FINDINGS: The database was used to examine retrospectively 15 drugs newly-marketed in the UK, with the highest levels of ADR reporting. The method identified 481 signals meeting the minimum criteria during the period 1996-8. Further evaluation of these showed that 70% were known adverse reactions, 13% were events which were likely to be related to the underlying disease and 17% were signals requiring further evaluation. IMPLICATIONS: Proportional reporting ratios are a valuable aid to signal generation from spontaneous reporting data which are easy to calculate and interpret, and various refinements are possible.

The Role of Medication Noncompliance and Adverse Drug Reactions in Hospitalizations of the Elderly

Abstract: • We interviewed 315 consecutive elderly patients admitted to an acute care hospital to determine the percentage of elderly hospital admissions due to noncompliance with medication regimens or adverse drug reactions, their causes, consequences, and predictors. Eighty-nine of the elderly admissions (28.2%) were drug related, 36 due to noncompliance (11.4%), and 53 due to adverse drug reactions (16.8%). One hundred three patients had a history of noncompliance (32.7%). Factors statistically associated with a higher risk of hospitalization due to noncompliance were poor recall of medication regimen, seeing numerous physicians, female, medium income category, use of numerous medications, and having the opinion that medications are expensive. Factors associated with an increased risk of an admission due to an adverse drug reaction were use of numerous different medications, higher medication costs, receiving Medicaid, and not receiving any home services. In conclusion, many elderly admissions are drug related; noncompliance accounting for a substantial fraction of these. Elders at high risk of being noncompliant are identifiable using a variety of criteria. Economic factors were important in predicting admissions due to noncompliance as well as adverse drug reactions. (Arch Intern Med.1990;150:841-845)