Objective: To determine the prevalence of hospital admissions associated with ADRs and examine differences in prevalence rates between population groups and methods of ADR detection. Data Sources: Studies were identified through electronic searches of Cumulative Index to Nursing and Allied Hearth Literature. EMBASE, and MEDLINE to August 2007. There were no language restrictions. Study Selection and Data Extraction: A systematic review was conducted of prospective observational studies that used the World Health Organization ADR definition. Subgroup analysis examined the influence of patient age groups and methods of ADR detection on reported ADR admission rates. All statistical analyses were performed using STATA v 9.0. Data Synthesis: Twenty-five studies were identified including 106, 586 patients who were hospitalized; 2143 of these patients had experienced ADRs. The prevalence rates of ADRs ranged from 0.16% to 15.7%, with an overall median of 5.3% (interquartile range [IQR] 2.7–9.0%). Median ADR prevalence rates varied between age groups: for children, the ADR admission rate was 4.1% (IQR 0.16–5.3%), while the corresponding rates for adults and elderly patients were 6.3% (IQR 3.9–9.0%) and 10.7% (IQR 9.6–13.3%), respectively. ADR rates also varied depending on the methods of ADR detection employed in the different studies. Studies that employed multiple ADR detection methods, such as medical record review and patient interview, reported higher ADR admission rates compared with studies that used medical record review alone. Antiinfective drugs were most often associated with ADR admissions in children; cardiovascular drugs were most often associated with ADR admissions in adults and elderly patients. Conclusions: Approximately 5.3% of hospital admissions were associated with ADRs. Higher rates were found in elderly patients who are likely to be receiving multiple medications for long-term illnesses. The methods used to detect ADRs are also likely to explain much of the variation in the reported ADR prevalence rates between different studies.

Centella asiatica (L.) Urb. has been used as an herbal brain tonic for mental disorders and enhancing memory, but no review of the overall evidence of C. asiatica and cognitive function has been conducted. This study aims to determine the effects of C. asiatica on cognitive function and its related properties. The current systematic review includes five randomized controlled trials (RCTs) conducted to determine the effect of C. asiatica alone and six RCTs conducted to determine the effect of C. asiatica-containing products. Meta-analysis indicated that there are no significant differences in all cognitive function domains of C. asiatica when compared to placebo. However, it could improve mood by increasing alert scores [SMD: 0.71 (95% CI; 0.01 to 1.41); I² = 30.5%] and decreasing anger scores at 1 hour after treatment [SMD: −0.81 (95%CI; −1.51 to −0.09); I² = 36.6%]. None of the studies reported adverse effects of C. asiatica. In conclusion, there is not strong evidence to support the use of C. asiatica for cognitive function improvement in each cognitive domain. C. asiatica could improve alertness and relieve anger. However, some limitations should be aware including dose regimen, plant preparation, standardization, and product variation. Future well-designed clinical trials using suitable doses of standardized C. asiatica are still needed.