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Biomedical subjects

R M Kaplan

Publications and source records attributed to R M Kaplan.

At least 19 recordsLinked to original sources

Development and characterization of microsatellite markers for the canine hookworm, Ancylostoma caninum.

Microsatellites are repetitive genomic elements that show high levels of variation and therefore provide excellent tools to study the genetics of eukaryotic organisms. Hookworms are extremely common and important nematode parasites of humans and animals, causing potentially serious disease morbidity. Control of hookworms in dogs is achieved by frequent treatment with anthelmintics, and in humans, anthelmintics are frequently administered in a mass-treatment community-wide approach. Understanding the population genetics of hookworms has important implications for studies on the development and spread of drug resistance. We investigated the genome of Ancylostoma caninum for microsatellites by developing and then screening an enriched genomic library as well as by data mining published sequences of a whole genome shotgun library. Investigations revealed a high abundance of trinucleotide repeats. Dinucleotide repeats were characterized by a high number of AT, GA, and GT repeats. After testing and optimization of 68 markers, a panel of 34 polymorphic microsatellite markers were selected. Microsatellite analysis of hookworm isolates revealed a high degree of polymorphism, which was not influenced by the length of the repeats. This panel of microsatellite markers makes it possible to pursue investigations on the population genetics of A. caninum. Furthermore, a number of the markers demonstrated suitability for analysis of the human hookworm species Necator americanus and A. duodenale.

Ancylostoma↗

Targeted selective treatment for worm management--how do we sell rational programs to farmers?

Seriously escalating global anthelmintic resistance in gastrointestinal nematodes of small ruminants has spawned a variety of alternatives to anthelmintics for worm management, based on the need for sustainable Integrated Parasite Management (sIPM). Pivotal to the sIPM approach is the concept of refugia, the proportion of a given parasite population that escapes exposure to control measures. By balancing drug applications with the maintenance of refugia, the accumulation of anthelmintic resistance alleles in worm populations can be considerably delayed, while still providing good levels of control. The over-dispersed nature of parasitic infections provides an opportunity to achieve this balance, by targeting treatments to the members of a flock or herd that are least tolerant to nematode infection. However, implementation of this strategy has only recently become feasible, with the development of the FAMACHA((c)) system for clinical evaluation of anaemia due to haemonchosis. Subsequently, the use of milk yields has proven an effective indicator in dairy goats infected predominantly with nematodes other than Haemonchus contortus. In addition, short-term weight changes and perhaps also body condition scoring may provide indices of parasitism, permitting the rapid identification of animals likely to benefit from treatment. However, sIPM and refugia-based approaches are more complex than whole-flock treatments in conventional programs, and adoption by farmers is most likely where the theoretical basis is understood. As close communication with informed advisors is generally limited, there is a danger that sIPM will remain a theoretical concept without alternative modes of communication. The development of computer-based decision support programs, which use epidemiological, seasonal and clinical information to provide recommendations for specific situations, should be accorded high priority in the future development of worm management systems.

Animal Husbandry↗

Sericea lespedeza hay as a natural deworming agent against gastrointestinal nematode infection in goats.

Infection with gastrointestinal nematodes (GIN), particularly Haemonchus contortus, is the biggest constraint to profitable goat production in the United States (US). Due to widespread prevalence of anthelmintic resistance in goat GIN, alternative, non-chemical control methodologies are needed to increase profitability of small ruminant industries. A study was designed to test the efficacy of a high condensed tannin (CT) legume, sericea lespedeza [SL, Lespedeza cuneata (Dum.-Cours. G. Don)] against GIN of goats fed in confinement. The goats were given a trickle infection of 500 H. contortus larvae/animal three times per week during the trial to simulate natural infection. Twenty Boer bucks (6-8 months old) were fed bermudagrass [BG, Cynodon dactylon (L.) Pers.] hay plus concentrate for 5 weeks in confinement and then 10 animals were switched to SL hay for an additional 7 weeks. Throughout the trial, feces and blood were collected weekly from individual animals to determine fecal egg count (FEC) and blood packed cell volume (PCV). Fecal cultures were made weekly from pooled samples to determine treatment effects on GIN larval development. All goats were slaughtered at the end of the trial, with adult worms in the abomasum and small intestine of each goat recovered, counted, and identified to species. Feeding SL hay to goats significantly (P<0.01) reduced FEC and increased PCV compared with BG hay. In addition, a lower percentage of ova in feces from SL-fed goats developed into infective (L3) larvae. There was a direct effect of SL hay on adult worms, with significantly (P<0.01) lower numbers of both abomasal (H. contortus, Teladorsagia circumcincta) and small intestinal (Trichostrongylus colubriformis) nematodes compared with goats fed BG hay. Feeding SL hay to goats is an effective means of controlling parasitic nematodes and may be a potential supplement/replacement for chemical anthelmintics.

Abomasum↗

Estimating the risk of long-term erectile, urinary and bowel symptoms resulting from prostate cancer treatment.

Reports on long-term complications resulting from treatment for localized prostate cancer are very inconsistent. In order to estimate the risks of long-term erectile dysfunction, urine symptoms and bowel symptoms following prostatectomy (RP), external conventional or conformal beam radiation (ERT or CRT) and brachytherapy (BRT), 98 papers from the PubMed and Cochrane Clinical Trial databases were selected, reviewed and critically evaluated. The majority of papers were institution-based retrospective and prospective follow-up studies; only two of these studies measured the risk of developing more than one treatment complication. Due to differences in study designs and populations, it is difficult to directly compare studies and not meaningful to calculate summary estimates. In addition to focusing on randomized clinical trials and well-designed population based studies, future research should adopt standardized methodologies and should measure the risk of developing more than one treatment complication.

Age Distribution↗

Isolation and characterisation of a beta tubulin isotype 2 gene from two species of cyathostomin.

This study describes the isolation and characterisation of beta tubulin isotype 2 cDNA sequences from two common species of cyathostomin, Cylicocyclus nassatus and Cyathostomum catinatum. The full-length cDNAs for these species were 1709 and 1753 bp in length, respectively, including 1350 bp of sequence inferred to encode 450 amino acids of peptide sequence. They had greatest identity with previously characterised isotype 2 sequences from Trichostrongylus colubriformis, Cooperia oncophora and Haemonchus contortus (96% for C. nassatus and 95% for C. catinatum), and grouped together with these sequences in phylogenetic analysis. Both cyathostomin beta tubulin isotype 2 sequences contained the isotype-specific carboxyl terminal region described previously in other nematode species. Alignment with beta tubulin isotype 1 proteins from other trichostrongyloids, indicated 95 and 94% identity for the isotype 2 sequences of C. nassatus and C. catinatum, respectively. This comparison revealed 14 isotype-specific amino acid substitutions. Also, 2605 bp of beta tubulin isotype 2 genomic DNA sequence were isolated from C. nassatus. Comparison with the previously published isotype 1 gene of C. nassatus indicated differences in genomic organisation between the two isotypes. Reverse transcriptase (RT)-polymerase chain reaction analysis revealed constitutive temporal expression of beta tubulin isotype 1, whilst isotype 2 appeared to be developmentally expressed, with transcripts detected only in RNA derived from adult parasites.

Animals↗

Effect of moxidectin selection on the genetic variation within Cylicocyclus nassatus based on amplified fragment length polymorphism (AFLP).

Cyathostomins are among the most important intestinal nematodes of horses, yet, the literature on the molecular genetics of these worms is scarce. In this study, the technique of amplified fragment length polymorphism (AFLP) was applied to study the genetic diversity as well as to determine the effect of moxidectin selection on the population genetic diversity for Cylicocyclus nassatus, one of the most common cyathostomin species. Genomic DNAs from 30 individual male worms were used from each of two populations: an avermectin-milbemycin (AM)-naive population (Population-S) and a population derived from Population-S following 21 treatments with moxidectin (Population-Mox). Three selective primer pairs were used for each worm, yielding a total of 229 AFLP markers. Calculation of average pair wise Jaccard indices revealed a high degree of genetic variation within both populations using all three primer combinations. In addition, selection by moxidectin during a 3-year period caused a significant decrease in the level of genetic diversity as evidenced by analysis of AFLP markers for two primer combinations but not for the third. A dendrogram of relationships among individuals based on AFLP markers did not show a clear classification of individuals in separate groups. It was concluded that a high degree of genetic intrapopulation variation exists in C. nassatus and that moxidectin selection has a significant effect on the genetic composition of C. nassatus.

Animals↗

Bermudagrass management in the Southern Piedmont USA. V: Gastrointestinal parasite control in cattle.

Parasite-free pastures would improve cattle health and performance, resulting in possible economic return to producers. Our objective was to determine the effect of a single series of anthelmintic treatment of steers prior to stocking on Coastal bermudagrass pastures, during five consecutive summers, on the parasite burden in cattle. The site for this experiment had been conventionally cropped for several decades, with no exposure to cattle, and would be expected to be relatively free of nematode larvae. The experimental design was a randomized complete block (landscape features) with a split plot arrangement of treatments where main plots were pasture fertilization treatments (mineral, clover plus mineral, and broiler litter) and split plots were low and high forage mass. Anthelmintic treatment included pour-on ivermectin on day -21, albendazole on day -7, and injectable ivermectin 48 h prior to stocking of pastures, with the cattle remaining in drylot during the 48-h period prior to being placed on the experimental paddocks. All steers received only one series of treatments during any given year. Yearling Angus steers (Bos taurus) were managed in a put-and-take grazing system with three "tester" steers assigned to each paddock and "grazer" steers added or removed at 28-day intervals. From 1994 to 1998, steers grazed the paddocks for a 140-day period from mid May until early October each year. Fecal samples for worm egg counts were obtained on day 0 and at 28-day intervals, thereafter. On all sampling days after day 0, samples were obtained only from tester animals. Over the 5-year period, the mean eggs per gram of feces (epg) gradually increased from 0 (following treatment) to a mean of 2.2 (range from 0.7 to 3.0) by the end of the grazing season (the last sampling date) in October. Although the epg were not zero, they were below threshold levels that would allow development of a parasite burden in cattle. In traditional management systems, cattle graze parasite-contaminated pastures; therefore, parasites negatively impact growth and productivity throughout the entire grazing period. Periodic anthelmintic treatments simply give a temporary reprieve from those parasitic infections. Conceptually, using the current grazing system, it should be possible to maintain these pastures in a parasite-free status indefinitely; however, from a drug resistance perspective, it would be most applicable in sod-based rotation systems where cattle graze from two to five years before land is returned to row-crops. By removing the effect of parasites, cattle can grow without the physiological constraints that gastrointestinal parasites place on appetite, digestion, nutrient utilization, and general well being.

Albendazole↗

Validation of the FAMACHA eye color chart for detecting clinical anemia in sheep and goats on farms in the southern United States.

Recent studies on sheep and goat farms in the southern United States indicate that multiple-anthelmintic resistance in Haemonchus contortus is becoming a severe problem. Though many factors are involved in the evolution of resistance, the proportion of the parasite population under drug selection is believed to be the single most important factor influencing how rapidly resistance develops. Therefore, where prevention of resistance is an important parallel goal of worm control, it is recommended to leave a portion of the animals untreated. Recently, a novel system called FAMACHA was developed in South Africa, which enables clinical identification of anemic sheep and goats. When H. contortus is the primary parasitic pathogen, this system can be applied on the farm level to reduce the number of treatments administered, thereby increasing the proportion of the worm population in refugia. Since most studies validating the FAMACHA method have been performed in South Africa, it is important that the method be tested in other regions before its use is broadly recommended. We performed a validation study of FAMACHA by testing the system in sheep (n = 847) and goats (n = 537) of various breeds and ages from 39 farms located in Arkansas, Georgia, Louisiana, Florida, and the US Virgin Islands. The color of the ocular conjunctiva of all animals were scored on a 1-5 scale using the FAMACHA card, and blood samples were collected from each animal for determination of packed cell volume (PCV). Fecal samples were also collected from a majority of the animals tested for performance of fecal egg counts (FEC). Correlations between PCV and eye scores, PCV and FEC, and FEC and eye scores were all highly significant for both sheep and goats (P < 0.001). Data for both FAMACHA scores and PCV were evaluated using two separate criteria for anemia: eye score values of 3, 4 and 5 or 4 and 5, and PCV values of < or =19 or < or =15 were considered anemic. Specificity was maximized when eye score values of 4 and 5 were considered anemic and PCV cut off for anemia was < or =19, but sensitivity was low. In contrast, sensitivity was 100% for both sheep and goats when eye score values of 3, 4 and 5 were considered anemic and PCV cut off was < or =15, but specificity was low. In both sheep and goats, predictive value of a negative was greater than 92% for all anemia and eye score categories, and was greater than 99% for both eye score categories when an anemia cutoff of < or =15 was used. Predictive value of a positive test was low under all criteria indicating that many non-anemic animals would be treated using this system. However, compared to conventional dosing practices where all animals are treated, a large proportion of animals would still be left untreated. These data indicate that the FAMACHA method is an extremely useful tool for identifying anemic sheep and goats in the southern US and US Virgin Islands. However, further studies are required to determine optimal strategies for incorporating FAMACHA-based selective treatment protocols into integrated nematode control programs.

Anemia↗

Evaluation of a larval development assay (DrenchRite) for the detection of anthelmintic resistance in cyathostomin nematodes of horses.

A larval development assay (LDA, DrenchRite) was evaluated to determine the effectiveness of this method in detecting anthelmintic resistance in cyathostomin nematodes of horses. A total of 15 horse farms from Georgia and South Carolina (USA) and Population S ponies from the University of Kentucky (USA) were included in this study. Nematode eggs were extracted from pooled fecal samples and placed into the wells of a DrenchRite plate for testing against thiabendazole (TBZ), levamisole (LEV) and 2 ivermectin (IVM) analogs (IVM-1, IVM-2). After a 7-day incubation larvae in each well were counted and data were analyzed by logistic regression. Resistance status of each farm for different drugs was determined in a separate study using a fecal egg count reduction test. LDA were performed on the 15 farms once, however, the Population S cyathostomins were assayed on 3 separate occasions to estimate the consistency of results between assays. Mean TBZ LC50 for oxibendazole resistant, suspected resistant and sensitive farms were 0.2015, 0.1625, and 0.1355 microM, respectively. For LEV, mean LC50 for PYR resistant, suspected resistant and sensitive farms were 1.590, 1.8018 and 1.4219 microM, respectively. All 15 farms had worms susceptible to IVM; mean LC50 for IVM-1 and for IVM-2 were 7.5727 and 87.9718 nM, respectively. A linear mixed model was fitted to the data to determine the relationship between LC50 and LC95 and resistance status for each farm. No meaningful relations were found. Consistency of assays varied between drugs, being best for TBZ and worst for LEV and IVM-1. All farms in this study had benzimidazole-resistant nematodes; therefore usefulness of DrenchRite for discriminating susceptibility versus resistance to this drug class could not be accurately assessed. Moreover, since all farms tested were sensitive to IVM and resistance to this drug class has not yet been reported in cyathostomins, it is not possible to assess accurately the usefulness of DrenchRite LDA for detecting IVM resistance at this time. Assay results for LEV suggest that LEV in a LDA does not yield data that is useful in estimating PYR efficacy in vivo. Based on results for PYR/LEV, the current high prevalence of benzimidazole resistance, no known cases of IVM resistance, and the sometimes extreme variation in results seen in many of the assays, DrenchRite LDA cannot be considered a useful tool for the diagnosis of resistance in cyathostomins of horses at present.

Animals↗

Capability of the nematode-trapping fungus Duddingtonia flagrans to reduce infective larvae of gastrointestinal nematodes in goat feces in the southeastern United States: dose titration and dose time interval studies.

Infection with gastrointestinal nematodes, particularly Haemonchus contortus, is a major constraint to goat production in the southeastern United States. Non-anthelmintic control alternatives are needed due to increasing resistance of these nematodes to available anthelmintics. Two studies were completed in Central Georgia in August 1999, and April-May 2000, using Spanish does naturally infected with Haemonchus contortus, Trichostongylus colubriformis, and Cooperia spp. to evaluate effectiveness of nematode-trapping fungi as a biological control agent. In the first experiment, five levels of Duddingtonia flagrans spores were mixed with a complete diet and fed once daily to the does (three per treatment) in metabolism crates. The treatment concentrations were (1) 5 x 10(5), (2) 2.5 x 10(5), (3) 10(5), and (4) 5 x 10(4) spores per kilogram body weight (BW), and (5) no spores. Fungal spores were fed for the first 7 days of the 14-day trial, and fecal samples were collected daily from individual animals for analysis of fecal egg count and establishment of fecal cultures. Efficacy of the fungus at reducing development of infective larvae (L3) in the fecal cultures was evaluated. The mean reduction in L3 from day 2 of the treatment period until the day after treatment stopped (days 2-8) was 93.6, 80.2, 84.1, and 60.8% for animals given the highest to lowest spore doses, respectively. Within 3-6 days after termination of fungal spore feedings, reduction in L3 development was no longer apparent in any of the treated animals. In a second experiment, effectiveness of 2.5 x 10(5) spores of D. flagrans per kilogram BW fed to does every day, every second day, and every third day was evaluated. Reduction in L3 development by daily feeding was less in the second experiment than in the first experiment. Daily fungal spore feeding provided more consistent larval reduction than intermittant feeding (every second or third day). When fed daily under controlled conditions, D. flagrans was effective in significantly reducing development of L3 and appears to be an effective tool for biocontrol of parasitic nematodes in goats.

Animals↗

Glycemia and the quality of well-being in patients with diabetes.

OBJECTIVES: To investigate the cross-sectional relationships among self-reported frequencies of symptomatic hyperglycemia and hypoglycemia, HbA1c, and symptoms in the Quality of Well-Being Self-Administered (QWB-SA), and to examine the associations among these measures of glycemia and health-utility scores. METHODS: The study group included 1522 patients with diabetes who attended University of Michigan Health System clinics. Published studies were reviewed to identify symptoms in the QWB-SA that might be associated with measures of glycemia. Linear-regression analyses were performed to evaluate the strength of the associations among the frequency of self-reported measures of glycemia, QWB-SA symptoms, and QWB-SA-derived health-utility scores. RESULTS: Frequency of hyperglycemic symptoms was associated with 3% of the variance in the QWB-SA-derived health-utility score in type-1 diabetes and with 5% of the variance in type-2 diabetes. Frequency of hypoglycemic symptoms was not associated with the QWB-SA-derived health-utility score in type-1 diabetes but was associated with 1% of the variance in type-2 diabetes. HbAlc levels were not significantly associated with QWB-SA-derived health-utility scores. After controlling for age, gender, and complications, frequency of hyperglycemic symptoms was significantly associated with QWB-SA-derived health-utility scores in type-1 and type-2 diabetes. CONCLUSIONS: Reported frequency of hyperglycemic symptoms is associated with symptoms included in the QWB-SA and with QWB-SA-derived health-utility scores. The QWB-SA may be an appropriate measure to assess the health burden of hyperglycemia.

Adolescent↗

Methodological issues in evaluating measures of health as outcomes for COPD.

The selection of an appropriate outcome measure depends on the aspect of the disease being addressed and the purpose of the study being conducted. The most fundamental property of any outcome is its ability to measure the biological variable under question. Other properties such as discriminative and evaluative abilities are also important. Specific outcomes measure a single biological variable, such as forced expiratory volume in one second or depression. The specificity of such measures is attractive but requires precise definition of what is being measured and why. Other, summative, outcomes are used to quantify the overall effect of a number of different biological processes. The simplest summative measures are global questions such as "How would you rate your health overall?" Others are complex with many items. If designed and used correctly, these questionnaires can provide an estimate of the overall impact of disease or response to therapy and an index of whether that response was clinically worthwhile. Standardisation of measurements is important to permit comparisons between patients and studies, which makes the measurement of an individual's "quality of life" difficult. The term "health-status measurement" may be better when referring to the use of standardised questionnaires. Utility-based measures help address concerns regarding clinical versus statistical improvement and place outcomes for chronic obstructive pulmonary disease treatment trials in the context of all healthcare treatments.

Aged↗

Anthelmintic resistance on goat farms in Georgia: efficacy of anthelmintics against gastrointestinal nematodes in two selected goat herds.

Gastrointestinal nematode (GIN) parasitism is a major constraint to production of goats in the southeastern United States. The conventional method of control used by producers in this region is frequent use of anthelmintics during the warm season. Overuse of anthelmintics has led to an increase in the incidence of anthelmintic resistance in many parts of the world, but data on prevalence of anthelmintic resistance in GIN of goats in the southeastern United States are very limited. To address this issue, anthelmintic efficacy was determined in goat herds at the Fort Valley State University, Agricultural Research Station (FVSU-ARS) and the University of Georgia, College of Veterinary Medicine (UGA-CVM) using fecal egg count reduction (FECR) tests and DrenchRite((R)) larval development assays (LDA). At FVSU-ARS, 2-year-old Spanish goat does were randomly allocated to one of nine different treatment groups (n = 10): albendazole (ABZ; 20mg/kg body weight (BW)), fenbendazole (FBZ; 20mg/kg BW), ivermectin (IVM; 0.4 mg/kg BW), doramectin (DRM; 0.4 mg/kg BW), moxidectin (MOX; 0.4 mg/kg BW), levamisole (LEV; 12 mg/kg BW), morantel tartrate (MOR; 10mg/kg BW), a combination of IVM (0.4 mg/kg BW) and ABZ (20 mg/kg BW), and untreated controls. At UGA-CVM, goats were randomly allocated to one of five different treatment groups (n = 8): ABZ (20 mg/kg BW), IVM (0.4 mg/kg BW), MOX (0.4 mg/kg BW), LEV (12 mg/kg BW), and untreated controls. All drugs in both experiments were administered orally. Anthelmintic efficacy was calculated by comparing 14-day post-treatment FEC of treated and control animals, and percent reductions were interpreted using the World Association for the Advancement of Veterinary Parasitology guidelines for resistance. For the LDA, nematode eggs were isolated from pooled fecal samples of untreated control goats in each herd and used to perform DrenchRite((R)) assays. In the FVSU-ARS herd, MOX, LEV, the combination of IVM and ABZ, IVM, DRM, ABZ, MOR, and FBZ reduced FEC by 100, 91, 88, 78, 76, 62, 48, and 10%, respectively. In the UGA-CVM herd, MOX, LEV, ABZ and IVM, reduced FEC by 100, 94, 87, and 0%, respectively. In both herds moxidectin was the only drug tested that was fully effective. Results of the LDA were in agreement with results of the FECR tests for both herds. These data demonstrate the presence of GINs resistant to all three major anthelmintic classes in both goat herds.

Animals↗

Prevalence and clinical implications of anthelmintic resistance in cyathostomes of horses.

OBJECTIVE: To determine the prevalence and clinical implications of anthelmintic resistance in cyathostomes of horses. DESIGN: Prospective study. ANIMALS: 80 horses on 10 farms in a 5-county region of northeast Georgia. PROCEDURE: On each farm, horses were stratified in descending order according to pretreatment fecal egg count (FEC), blocked into groups of 4, and then randomly assigned to 1 of 4 treatment groups: no treatment (controls), and treatment with pyrantel pamoate, fenbendazole, or ivermectin. Fecal samples were collected 24 hours prior to treatment and 2, 4, and 6 weeks after treatment for determination of FEC. Mean percentage of reduction in FEC was then calculated for each treatment group. For horses from each farm, the efficacy of each anthelmintic was categorized on the basis of mean percentage of reduction in FEC at 2 weeks after treatment (< 80% reduction = ineffective; 80 to 90% reduction = equivocal; and > 90% reduction = effective). RESULTS: Pyrantel pamoate was effective at reducing FEC in horses from 7 farms, ineffective in horses from 2 farms, and equivocal in horses from 1 farm. Fenbendazole was ineffective at reducing FEC in horses from 9 farms and equivocal in horses from 1 farm. Ivermectin was effective at reducing FEC in horses from all 10 farms. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cyathostome resistance to fenbendazole is highly prevalent, and resistance to pyrantel pamoate is high enough to warrant concern. Resistance to ivermectin was not detected. On the basis of these data, it appears that ivermectin continues to be fully effective in horses. However, too few farms were used in this study to determine the prevalence of cyathostome resistance to ivermectin. Therefore, the efficacy of ivermectin should continue to be monitored closely.

Animals↗

Economic analysis of lung volume reduction surgery as part of the National Emphysema Treatment Trial. NETT Research Group.

BACKGROUND: In today's cost-conscious health care environment, obtaining timely and accurate economic information regarding new medical technologies has become extremely important. The National Emphysema Treatment Trial, a multicenter, randomized controlled trial of lung volume reduction surgery (LVRS) plus medical therapy, versus medical therapy for patients with severe emphysema, includes a parallel cost-effectiveness analysis. METHODS: The analysis is designed to determine the cost-effectiveness of LVRS versus medical therapy for those who are eligible for the procedure. After describing theoretical foundations of cost-effectiveness analysis as they apply to this study, we describe the economic and quality of life data that are being collected alongside the clinical trial, methods of analysis, and approach to presenting the results. RESULTS: The cost-effectiveness of LVRS relative to medical therapy will be presented as costs per quality-adjusted life years gained. CONCLUSIONS: This analysis will provide timely economic data that can be considered alongside the clinical results of the National Emphysema Treatment Trial. As one of the largest clinical trials to include a parallel, prospective cost-effectiveness analyses, this study will also provide valuable practical information about conducting an economic analysis alongside a multicenter clinical trial.

Cost-Benefit Analysis↗