Iron deficiency anemia prevalence at first stroke or transient ischemic attack.

BACKGROUND: Iron deficiency anemia (IDA) has been implicated in the etiology of transient ischemic attack and ischemic stroke. This study aimed to: 1) document IDA prevalence in patients ≥ 65 years of age admitted to hospital with transient ischemic attack or first ischemic stroke, and 2) investigate dietary intake as a predictor of iron status. METHODS: Ninety-four patients were enrolled. An algorithm containing values for hemoglobin, ferritin, total iron binding capacity, transferrin saturation, and serum transferrin receptor measured at admission was used to identify IDA. Usual dietary intake was assessed with the Clue II food frequency questionnaire. RESULTS: Prevalence estimates were 6.4% for IDA, 2.1% for iron deficiency without anemia, and 6.4% for anemia from other causes. IDA prevalence was significantly higher than published National Health and Nutrition Examination Survey III (NHANES III) estimates for gender-specific age groups ≥ 70 years (One-Sample Proportion Test; males p = 0.038 [n= 37]; females p = 0.002 [n=44]). A comparison of IDA prevalence against selected controls from the NHANES III database yielded an odds ratio (OR) of 6.3, 95% confidence interval (CI) 0.8 to 53.7, which was not statistically significant (Fisher's Exact Test; n=94; p = 0.118). Multivariate linear regression analysis of dietary intake with indicators of iron status (n=58) revealed only iron supplements (p = 0.013) and heme iron intake (p = 0.038) as negative predictors of total iron binding capacity (p<0.05). CONCLUSIONS: These findings support the initiation of a prospective case control study to investigate IDA as a risk factor for ischemic stroke in elderly patients.

Comparison of life cycle carbon dioxide emissions and embodied energy in four renewable electricity generation technologies in New Zealand.

In order to make the best choice between renewable energy technologies, it is important to be able to compare these technologies on the basis of their sustainability, which may include a variety of social, environmental, and economic indicators. This study examined the comparative sustainability of four renewable electricity technologies in terms of their life cycle CO2 emissions and embodied energy, from construction to decommissioning and including maintenance (periodic component replacement plus machinery use), using life cycle analysis. The models developed were based on case studies of power plants in New Zealand, comprising geothermal, large-scale hydroelectric, tidal (a proposed scheme), and wind-farm electricity generation. The comparative results showed that tidal power generation was associated with 1.8 g of CO2/kWh, wind with 3.0 g of CO2/kWh, hydroelectric with 4.6 g of CO2/kWh, and geothermal with 5.6 g of CO2/kWh (not including fugitive emissions), and that tidal power generation was associated with 42.3 kJ/kWh, wind with 70.2 kJ/kWh, hydroelectric with 55.0 kJ/kWh, and geothermal with 94.6 kJ/kWh. Other environmental indicators, as well as social and economic indicators, should be applied to gain a complete picture of the technologies studied.

Treatments for carpal tunnel syndrome: who does what, when ... and why?

OBJECTIVE: To determine how frequently treatments had been offered to patients with suspected diagnoses of carpal tunnel syndrome (CTS) who had been referred for confirmatory nerve conduction studies (NCSs) and to identify potential predictors of such treatment. A follow-up survey was conducted to determine the effect of NCS results on subsequent treatment. DESIGN: Self-administered survey questionnaire and follow-up telephone survey. SETTING: Royal University Hospital at the University of Saskatchewan in Saskatoon. PARTICIPANTS: Two hundred eleven patients with clinically suspected CTS who had been referred for confirmatory NCS. MAIN OUTCOME MEASURES: Results of NCSs, number of patients prescribed wrist splints or nonsteroidal anti-inflammatory drugs (NSAIDs) before and after NCSs, patient characteristics associated with being prescribed therapy, and reporting benefit of therapy. RESULTS: Nerve conduction studies confirmed CTS in 121 (57.3%) of the 211 study patients. Before NCSs, wrist splints and NSAIDs had been prescribed to 33.2% and 38.8% of patients, respectively. Splints and NSAIDs were reported to alleviate symptoms by 78.3% and 74% of patients, respectively, who received such treatments. No significant differences in age, sex, body mass index, symptom duration, symptom or function scores, or subsequent NCS results were noted between patients who were and were not prescribed these therapies or between those who did or did not report improvement in symptoms. Results of the follow-up survey indicated that the number of recommendations for splints and NSAIDs had doubled after NCSs were completed and that surgical intervention had been at least discussed in most cases. Treatment recommendations, including surgery, however, were not associated with identifiable patient factors, including patients' NCS results. CONCLUSION: Some patients were prescribed conservative treatments before NCSs. Following NCSs, prescriptions for wrist splints or NSAIDs approximately doubled. Interestingly, NCS results did not appear to influence subsequent therapeutic decision-making for either conservative treatment or surgical options. We think these findings suggest a lack of confidence in electrodiagnostic study results. It would be interesting to evaluate a larger population of primary care patients prospectively to examine further the use of NCSs in current clinical decision-making.