Seasonality and toxin production of Pyrodinium bahamense in a Red Sea lagoon.

Harmful algal blooms of the dinoflagellate Pyrodinium bahamense have caused human and economic losses in the last decades. This study, for the first time, documents a bloom of P. bahamense in the Red Sea. The alga was recurrently present in a semi-enclosed lagoon throughout nearly 2 years of observations. The highest cell densities (104-105cellsL-1) were recorded from September to beginning of December at temperatures and salinities of ∼26-32°C and ∼41, respectively. The peak of the bloom was recorded mid-November, before a sharp decrease in cell numbers at the end of December. Minimum concentrations in summer were at ∼103cellsL-1. A saxitoxin ELISA immunoassay of cultures and water samples confirmed the toxicity of the strain found in the Red Sea. Moreover, a gene expression analysis of the saxitoxin gene domain SxtA4 showed that transcript production peaked at the culmination of the bloom, suggesting a relation between transcript production, sudden cells increment-decline, and environmental factors.

Results of provider self-adjudication using the prudent layperson standard compared with the managed care organization's emergency department claim review process.

STUDY OBJECTIVES: We compare the results of a provider "self-adjudicating" outpatient emergency department claims using a "presenting symptom-based" system with the managed care organization (MCO) adjudicating the claims using a "final diagnosis-based" system. METHODS: All outpatient visits from one MCO to an urban, university hospital between January 1, 1998, and February 28, 1999, were included. Each record was reviewed by 2 methods to determine whether the visit qualified for payment under the MCO's benefit structure. Under the provider adjudication, symptom-based system, all visits with nursing triage levels of immediate/emergency were approved automatically. Those with triage levels of delayed/nonurgent were reviewed by an emergency physician and approved if, in the physician's opinion, the presenting symptoms met the emergency criteria under the District of Columbia's Access to Emergency Services Act. A second claims review, blinded to the first, was performed with the diagnosis-based system used by the MCO before approval of the prudent layperson standard. This review divided the records into "approve," "deny," and "suspend" categories according to the discharge International Classification of Diseases, ninth revision code. The results of the 2 reviews were compared. RESULTS: We reviewed 1,830 records; 836 (46%) cases were triaged as immediate/emergency and 994 (54%) as delayed/nonurgent. Of the 994 delayed/nonurgent visits, physician review determined that 607 (61%) met the prudent layperson standard and 387 (39%) did not. Overall, the provider self-adjudication system determined that 1,443 (78.8%) of the 1,830 visits should be approved for insurance coverage. The MCO's system approved 966 (53%), denied 335 (18%), and suspended 529 (29%). Provider self-adjudication using a symptom-based system resulted in the immediate approval of 1,443 (77.8%) visits compared with 966 (52.7%) by a diagnosis-based system (P <.001). Excluding the 529 suspended claims, McNemar's statistical testing of 1,302 records failed to demonstrate the equivalence of the 2 systems (P <. 001). CONCLUSION: Compared with the standard ED claims review process used by the managed care industry, provider self-adjudication using a symptom-based system approves a greater proportion of visits, avoids rejection of many ED visits, and identifies many nonemergency visits that mistakenly appear to be emergencies. The possibility of providers and MCOs working together to adjudicate outpatient ED claims should be explored.