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PubMed2000

A diagnostic algorithm for carpal tunnel syndrome based on Bayes's theorem.

OBJECTIVE: To construct a diagnostic algorithm based on Bayes's theorem and using simple clinical tests to allow accurate diagnosis without resort to nerve conduction studies. METHOD: A cohort of patients being referred with possible carpal tunnel syndrome had clinical and electrophysiological testing, from which the simple calculations for sensitivity, specificity and prevalence were made and subsequently used in the formula of Bayes's theorem. The algorithm was then tested prospectively in a further cohort of similarly referred patients. RESULTS: The algorithm proved to be reliable when tested prospectively, and was similar to nerve conduction studies in diagnostic accuracy. CONCLUSION: A simple algorithm of clinical tests can identify patients without resort to nerve conduction studies, facilitating early treatment.

Algorithms↗

PubMed2004

A novel adaptive wrist actigraphy algorithm for sleep-wake assessment in sleep apnea patients.

STUDY OBJECTIVES: Current actigraphic algorithms are relatively less accurate in detecting sleep and wake in sleep apnea patients than in people without sleep apnea. In the current study, we attempted to validate a novel automatic algorithm, which was developed for actigraphic studies in normal subjects and patients with obstructive sleep apnea by comparing it on an epoch-by-epoch basis to standard polysomnography. DESIGN: Prospective cohort study. SETTING: Multicenter, university hospital, sleep laboratories. PARTICIPANTS: A total of 228 subjects from 3 different sleep centers (Skara, Boston, Haifa) participated. INTERVENTION AND MEASUREMENTS: Simultaneous recording of polysomnography and Watch_PAT100, an ambulatory device that contains a built-in actigraph. The automatic sleep/wake algorithm is based on both the quantification of motion (magnitude and duration) and the various periodic movement patterns, such as those occurring in patients with moderate to severe obstructive sleep apnea. RESULTS: The overall sensitivity and specificity to identify sleep was 89% and 69%, respectively. The agreement ranged from 86% in the normal subjects to 86%, 84%, and 80% in the patients with mild, moderate, and severe obstructive sleep apnea, respectively. There was a tight agreement between actigraphy and polysomnography in determining sleep efficiency (78.4 +/- 9.9 vs 78.8 +/- 13.4%), total sleep time (690 +/- 152 vs 690 +/- 154 epochs), and sleep latency (56.8 +/- 31.4 vs 43.3 +/- 45.4 epochs). While for most individuals the difference between the polysomnography and actigraphy was relatively small, for some there was a substantial disagreement. CONCLUSIONS: We conclude that this actigraphy algorithm provides a reasonably accurate estimation of sleep and wakefulness in normal subjects and patients with obstructive sleep apnea on an epoch-by-epoch basis. This simple method for assessment of total sleep time may provide a useful tool for the accurate quantification of obstructive sleep apnea in the home environment.

Adaptation, Physiological↗

PubMed1999

Thromboelastography-guided transfusion algorithm reduces transfusions in complex cardiac surgery.

UNLABELLED: Transfusion therapy after cardiac surgery is empirically guided, partly due to a lack of specific point-of-care hemostasis monitors. In a randomized, blinded, prospective trial, we studied cardiac surgical patients at moderate to high risk of transfusion. Patients were randomly assigned to either a thromboelastography (TEG)-guided transfusion algorithm (n = 53) or routine transfusion therapy (n = 52) for intervention after cardiopulmonary bypass. Coagulation tests, TEG variables, mediastinal tube drainage, and transfusions were compared at multiple time points. There were no demographic or hemostatic test result differences between groups, and all patients were given prophylactic antifibrinolytic therapy. Intraoperative transfusion rates did not differ, but there were significantly fewer postoperative and total transfusions in the TEG group. The proportion of patients receiving fresh-frozen plasma (FFP) was 4 of 53 in the TEG group compared with 16 of 52 in the control group (P < 0.002). Patients receiving platelets were 7 of 53 in the TEG group compared with 15 of 52 in the control group (P < 0.05). Patients in the TEG group also received less volume of FFP (36 +/- 142 vs 217 +/- 463 mL; P < 0.04). Mediastinal tube drainage was not statistically different 6, 12, or 24 h postoperatively. Point-of-care coagulation monitoring using TEG resulted in fewer transfusions in the postoperative period. We conclude that the reduction in transfusions may have been due to improved hemostasis in these patients who had earlier and specific identification of the hemostasis abnormality and thus received more appropriate intraoperative transfusion therapy. These data support the use of TEG in an algorithm to guide transfusion therapy in complex cardiac surgery. IMPLICATIONS: Transfusion of allogeneic blood products is common during complex cardiac surgical procedures. In a prospective, randomized trial, we compared a transfusion algorithm using point-of-care coagulation testing with routine laboratory testing, and found the algorithm to be effective in reducing transfusion requirements.

Aged↗

PubMed1997

An algorithm for assessing intraoperative mean arterial pressure lability.

BACKGROUND: Intraoperative blood pressure lability may be related to risk factors, hypovolemia, light anesthesia, and morbid outcomes, but the measurements of lability in previous studies have been limited by imprecise and infrequent data collection methods. Computerized intraoperative data acquisition systems have provided an opportunity to readdress the issue of intraoperative blood pressure lability with more abundant and precise data. This study sought to derive and validate an algorithm (expert system) to measure mean arterial pressure (MAP) lability. METHODS: Two hundred thirty-nine computerized anesthesis records were reviewed retrospectively. Three anesthesiologists separately rated MAP as very stable, average, or very labile. The parameters of a computer algorithm that measured the change of median MAP between consecutive 2-min epochs were optimized to achieve the best possible agreement among the anesthesiologists. The algorithm was then validated on 229 additional anesthesia records. RESULTS: The proportion of consecutive 2-min epochs in which the absolute value of the fractional change of median MAP exceeded 0.06 (i.e., 6%) correlated strongly with the anesthesiologists' ratings (r = 0.78; P < 0.0001). The optimal sensitivity and specificity of the algorithm for detecting MAP lability were 98% and 59%, respectively. CONCLUSIONS: One potential application of expert systems to anesthesia practice is a "smart alarm" to detect blood pressure lability. It may also provide a better tool to assess the relation between lability and outcome than has been available previously.

Algorithms↗

PubMed2003

Improving lopinavir genotype algorithm through phenotype correlations: novel mutation patterns and amprenavir cross-resistance.

BACKGROUND: Current genotypic algorithms suggest that the HIV-1 protease inhibitors (PI) lopinavir (LPV) and amprenavir (APV) have distinct resistance profiles. However, phenotypic data indicate that cross-resistance is more common than expected. METHODS: Protease genotype (GT) and phenotype (PT) from 1418 patient viruses with reduced PI susceptibility and/or resistance-associated mutations (training data) were analyzed. Samples were classified as LPV resistant by GT (GT-R) if six or more LPV mutations were present, and by PT (PT-R) if the 50% inhibitory concentration (IC(50)) fold-change (FC) was over 10. RESULTS: There were 182 samples (13%) that were GT-S but PT-R for LPV. A comparison of the mutation prevalence in PT-R/GT-S samples with that in PT-S/GT-S samples identified mutations associated with LPV PT-R. Several previously defined LPV mutations were found to have a stronger than average effect (e.g., M46I/L, I54V/T, V82A/F), and new variants at known positions (e.g., I54A/M/S, V82S) were identified. Other mutations, including known APV resistance mutations, were found to contribute to reduced LPV susceptibility. A new LPV genotypic interpretation algorithm was constructed that improved overall genotypic/phenotypic concordance from 80% to 91%. The algorithm demonstrated a concordance rate of 90% when tested on 523 new samples. Cross-resistance between APV and LPV was greater in samples with primary APV resistance mutations than in those lacking them. CONCLUSIONS: The current LPV mutation score does not fully account for many resistant viruses. Consequently, cross-resistance between LPV and APV is underappreciated. Phenotypic results from large and diverse patient virus populations should be used to guide the development of more accurate GT interpretation algorithms.

Algorithms↗

PubMed2002

A new algorithm for ptosis repair using conjunctival Müllerectomy with or without tarsectomy.

PURPOSE: To determine the predictability of a new algorithm for determining the amount of tissue resection for conjunctival Müllerectomy with or without tarsectomy blepharoptosis repair. METHODS: Consecutive case series of all patients undergoing conjunctival Müllerectomy with or without tarsectomy ptosis repair from October 1999 to September 2001. Each patient underwent excision according to a new algorithm for determining the amount of tissue excision. The amount resected was determined by the following formula: 9 mm of conjunctiva and Müller muscle + x mm of tarsus, where x = distance of undercorrection after phenylephrine testing. RESULTS: Sixty-eight consecutive patients underwent 70 cases of conjunctival Müllerectomy with or without tarsectomy ptosis repair on 117 eyelids, using a new algorithm for tissue excision. Forty-seven cases were bilateral and 23 were unilateral. Postoperative symmetry was found in 58 of 67 patients (87%) after 1 surgery. Patient satisfaction based on symmetry, contour, and height after 1 repair was achieved in 64 of 67 patients. There were no overcorrections. Two patients underwent successful reoperation with a second conjunctival Müllerectomy with or without tarsectomy operation. CONCLUSIONS: This modified algorithm and technique quantifies conjunctival Müllerectomy with or without tarsectomy ptosis surgery and yields predictable results.

Algorithms↗

PubMed1988

Design and prospective evaluation of an algorithm for penetrating truncal injuries.

The major aim was to develop a branch-chain decision tree for penetrating truncal injury and to subject this to a prospective trial of its feasibility to track management decisions. In contrast to the conventional trauma study which focuses on highly selected, well-defined surgical problems, this algorithmic approach was designed to look at the whole gamut of problems of unselected patients with penetrating injury as they enter the ED. The branch-chain algorithm primarily focuses on priorities, order of procedures, and the immediate therapeutic options. The algorithm was used to track clinical management of 280 consecutive patients with penetrating truncal injuries; 31 were dead on arrival, 12 were alive on admission but died during their hospitalization. Of 209 patients whose management was in satisfactory compliance, four (2%) died; eight (20%) of 40 patients who had major deviations from the algorithm died (p less than .01).

Algorithms↗

PubMed1995

Sensitivity of a mixed field dosimetry algorithm to uncertainties in thermoluminescent element readings.

An error analysis of the effects of the algorithms used to resolve the deep and shallow dose components for mixed fields from multi-element thermoluminescent (TLD) badge systems was undertaken for a commonly used system. Errors were introduced independently into each of the four element readings for a badge, and the effects on the calculated dose equivalents were observed. A normal random number generator was then utilized to introduce simultaneous variations in the element readings for different uncertainties. The Department of Energy Laboratory Accreditation Program radiation fields were investigated. Problems arising from the discontinuous nature of the algorithm were encountered for a number of radiation sources for which the algorithm misidentified the radiation field. Mixed fields of low energy photons and betas were found to present particular difficulties for the algorithm. The study demonstrates the importance of small fluctuations in the TLD element's response in a multi-element approach.

Algorithms↗

PubMed2006

Predictability analysis for an automated seizure prediction algorithm.

Epileptic seizures of mesial temporal origin are preceded by changes in signal properties detectable in the intracranial EEG. A series of computer algorithms designed to detect the changes in spatiotemporal dynamics of the EEG signals and to warn of impending seizures have been developed. In this study, we evaluated the performance of a novel adaptive threshold seizure warning algorithm (ATSWA), which detects the convergence in Short-Term Maximum Lyapunov Exponent (STLmax) values among critical intracranial EEG electrode sites, as a function of different seizure warning horizons (SWHs). The ATSWA algorithm was compared to two statistical based naïve prediction algorithms (periodic and random) that do not employ EEG information. For comparison purposes, three performance indices "area above ROC curve" (AAC), "predictability power" (PP) and "fraction of time under false warnings" (FTF) were defined and the effect of SWHs on these indices was evaluated. The results demonstrate that this EEG based seizure warning method performed significantly better (P < 0.05) than both naïve prediction schemes. Our results also show that the performance indexes are dependent on the length of the SWH. These results suggest that the EEG based analysis has the potential to be a useful tool for seizure warning.

Adult↗

PubMedDate not supplied

Rapid automated algorithm for aligning and reslicing PET images.

A computer algorithm for the three-dimensional (3D) alignment of PET images is described. To align two images, the algorithm calculates the ratio of one image to the other on a voxel-by-voxel basis and then iteratively moves the images relative to one another to minimize the variance of this ratio across voxels. Since the method relies on anatomic information in the images rather than on external fiducial markers, it can be applied retrospectively. Validation studies using a 3D brain phantom show that the algorithm aligns images acquired at a wide variety of positions with maximum positional errors that are usually less than the width of a voxel (1.745 mm). Simulated cortical activation sites do not interfere with alignment. Global errors in quantitation from realignment are less than 2%. Regional errors due to partial volume effects are largest when the gantry is rotated by large angles or when the bed is translated axially by one-half the interplane distance. To minimize such partial volume effects, the algorithm can be used prospectively, during acquisition, to reposition the scanner gantry and bed to match an earlier study. Computation requires 3-6 min on a Sun SPARCstation 2.

Algorithms↗

PubMedDate not supplied

Comparison of projection algorithms used for the construction of maximum intensity projection images.

OBJECTIVE: Four methods of producing maximum intensity projection (MIP) images were studied and compared. MATERIALS AND METHODS: Three of the projection methods differ in the interpolation kernel used for ray tracing. The interpolation kernels include nearest neighbor interpolation, linear interpolation, and cubic convolution interpolation. The fourth projection method is a voxel projection method that is not explicitly a ray-tracing technique. The four algorithms' performance was evaluated using a computer-generated model of a vessel and using real MR angiography data. The evaluation centered around how well an algorithm transferred an object's width to the projection plane. RESULTS: The voxel projection algorithm does not suffer from artifacts associated with the nearest neighbor algorithm. Also, a speed-up in the calculation of the projection is seen with the voxel projection method. Linear interpolation dramatically improves the transfer of width information from the 3D MRA data set over both nearest neighbor and voxel projection methods. Even though the cubic convolution interpolation kernel is theoretically superior to the linear kernel, it did not project widths more accurately than linear interpolation. A possible advantage to the nearest neighbor interpolation is that the size of small vessels tends to be exaggerated in the projection plane, thereby increasing their visibility. CONCLUSION: The results confirm that the way in which an MIP image is constructed has a dramatic effect on information contained in the projection. The construction method must be chosen with the knowledge that the clinical information in the 2D projections in general will be different from that contained in the original 3D data volume.

Algorithms↗

PubMedDate not supplied

Reliability and validity of an algorithm for fuzzy tissue segmentation of MRI.

PURPOSE: A new multistep, volumetric-based tissue segmentation algorithm that results in fuzzy (or probabilistic) voxel description is described. This algorithm is designed to accurately segment gray matter, white matter, and CSF and can be applied to both single channel high resolution and multispectral (multiecho) MR images. METHOD: The reliability and validity of this method are evaluated by assessing (a) the stability of the algorithm across time, rater, and pulse sequence; (b) the accuracy of the method when applied to both real and synthetic image datasets; and (c) differences in specific tissue volumes between individuals with a specific genetic condition (fragile X syndrome) and normal control subjects. RESULTS: The algorithm was found to have high reliability, accuracy, and validity. The finding of increased caudate gray matter volume associated with the fragile X syndrome is replicated in this sample. CONCLUSION: Since this segmentation approach incorporates "fuzzy" or probabilistic methods, it has the potential to more accurately address partial volume effects, anatomical variation within "pure" tissue compartments, and more subtle changes in tissue volumes as a result of disease and treatment. The method is a component of software that is available in the public domain and has been implemented on an inexpensive personal computer thus offering an attractive and promising method for determining the status and progression of both normal development and pathology of the CNS.

Adolescent↗

PubMed2004

Comprehensive algorithm for skull base dural lesion and cerebrospinal fluid fistula diagnosis.

OBJECTIVES/HYPOTHESIS: Skull base dural lesions and cerebrospinal fluid (CSF) fistulas are potentially vital conditions whose diagnosis can be challenging. The authors' aim was to compose a comprehensive algorithm that combines the most modern diagnostic tools in easily applicable patterns to indicate a possible dural lesion or CSF fistula. STUDY DESIGN: Prospective clinical study. METHODS: The authors collected the data of all patients with suspicion of CSF fistula or dural lesion, or both, between January 1999 and December 2002. Beta-trace protein, beta2-transferrin, and endoscopic and laboratory sodium fluorescein tests; high-resolution computed tomography; and magnetic resonance cisternography were used according to the symptoms and etiological factors. The results of the diagnostic tools that were used and intraoperative findings (in case of an operative treatment) were reviewed. RESULTS: From 1999 to 2002, 236 patients were evaluated because of suspicion of dural lesion or CSF fistula, mostly after head trauma. Pattern I of the algorithm was applied for head trauma in dural lesion or CSF leak assessment, pattern II for postoperative CSF leaks, pattern III for evaluation of spontaneous CSF rhinorrhea, and pattern IV for the assessment of recurrent pneumococcal meningitis related to dural lesions without CSF fistula. By applying the patterns of this algorithm, a dural lesion or CSF leak that was also confirmed intraoperatively was detected in 48 patients. CONCLUSION: The four patterns of the new diagnostic algorithm described in the present study enable physicians to reliably clarify suspicions of dural lesions and CSF fistulas and aim to help them choose the best possible management. Each pattern uses the optimal combination of CSF tests and radiological imaging to reach a synergistic effect for precisely detecting dural lesions or CSF fistulas. Accordingly, this improves surgical decision-making when necessary.

Adolescent↗

PubMed2000

Improvement of clinical algorithms for the diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis by the use of Gram-stained smears among female sex workers in Accra, Ghana.

BACKGROUND: Screening for cervical infection is difficult in developing countries. Screening strategies must be improved for high-risk women, such as female sex workers. GOAL: To evaluate the sensitivity and specificity of screening algorithms for cervical infection pathogens among female sex workers in Accra, Ghana. STUDY DESIGN: A cross-sectional study among female sex workers was conducted. Each woman underwent an interview and a clinical examination. Biologic samples were obtained for the diagnosis of HIV, syphilis, bacterial vaginosis, yeast infection, Trichomonas vaginalis, Neisseria gonorrhoeae, and Chlamydia trachomatis infection. Signs and symptoms associated with cervicitis agents were identified. Algorithms for the diagnosis of cervical infection were tested by computer simulations. RESULTS: The following prevalences were observed: HIV, 76.6%; N. gonorrhoeae, 33.7%; C. trachomatis, 10.1%; candidiasis, 24.4%; T. vaginalis, 31.4%; bacterial vaginosis, 2.3%; serologic syphilis, 4.6%; and genital ulcers on clinical examination, 10.6%. The best performance of algorithms were reached when using a combination of clinical signs and a search for gram-negative diplococci on cervical smears (sensitivity, 64.4%; specificity, 80.0%). CONCLUSIONS: In the algorithms, examination of Gram-stained genital smears in female sex workers without clinical signs of cervicitis improved sensitivity without altering specificity for the diagnosis of cervical infection.

Adult↗

PubMed2003

Algorithm for the diagnosis of HER-2/neu status in breast-infiltrating carcinomas.

Determination of HER-2/neu overexpression/amplification is becoming increasingly important. The aim of this study is to elaborate an algorithm for the diagnosis of Her-2/neu status in breast-infiltrating carcinomas. Three hundred five breast-infiltrating carcinomas were selected to determine HER-2/neu overexpression by immunohistochemistry with two different methods: the monoclonal antibody CB11 and the HercepTest. Fluorescence in situ hybridization (FISH) was performed in a subgroup of those cases. Time-consuming and reagent costs were calculated for each of the procedures. HER-2/neu overexpression was found in 16% and 33% of the tumors with the monoclonal antibody (mAb) CB11 and with the HercepTest, respectively. There were 50 cases with immunohistochemical discordant results; most of them were HercepTest score 2+/mAb CB11 negative (37/50). Of those cases, only 27% presented gene amplification. The algorithm consisted of testing all the specimens with the mAb CB11 for selection of positive cases, negative cases are confirmed with the HercepTest, and FISH is performed only in those cases with immunohistochemical discordant results. The algorithm rate of HER-2/neu positivity in our series was 22%. Time and costs are reduced by 60% and 41%, respectively, compared to FISH. The use of the algorithm is feasible, accurate, and cost-effective in relation to FISH.

Algorithms↗

PubMed2005

Use of a treatment algorithm to achieve NCEP ATP III goals with atorvastatin.

This multicenter, 8-week, single-step titration, open-label study sought to assess the percentage of subjects who achieved their National Cholesterol Education Program Adult Treatment Panel (NCEP ATP) III low-density lipoprotein (LDL)-cholesterol target when assigned a starting dose of atorvastatin (10 mg, 20 mg, 40 mg, or 80 mg) selected using an algorithm based on their 10-year CHD risk and the magnitude of LDL-cholesterol lowering necessary to reach goal. Following an 8-week washout period, 1298 subjects, categorized as low, medium, or high risk, were assigned to 4 weeks of treatment with a starting dose of atorvastatin selected by the algorithm. At week 4, subjects who did not achieve goal (15.8%) were titrated to the next-higher dose. The primary endpoint was the percentage of subjects in each risk group who achieved LDL-cholesterol goal at week 8. At 8 weeks, 84.8% of subjects (low risk 92.9%; moderate risk 84.0%; high risk 81.1%) achieved LDL-cholesterol target. The majority of patients (84.2%) achieved their lipid target through the use of the algorithm-based starting dose (10-80 mg) without the need for titration. No patient had elevations in creatine phosphokinase >10 times the upper limit of normal. Elevations in alanine aminotransaminase or aspartate aminotransaminase were observed in <1% of study subjects and were unrelated to dose. Selecting the starting dose of atorvastatin using a treatment algorithm achieves NCEP ATP III LDL-cholesterol goals in the majority of patients and minimizes the need for dose titration.

Adolescent↗

PubMed2003

The New York University nerve sparing algorithm decreases the rate of positive surgical margins following radical retropubic prostatectomy.

PURPOSE: We developed an algorithm that prospectively defines when to excise the neurovascular bundles during radical retropubic prostatectomy with the goal of maximizing the performance of nerve sparing procedures while minimizing positive surgical margins. MATERIALS AND METHODS: From January 1 to December 31, 2000 a single surgeon performed 272 radical retropubic prostatectomies and 263 were performed from January 1 to December 31, 2001. A single pathologist analyzed all specimens with positive margins. There were no prospectively defined criteria to guide decisions regarding excision of the neurovascular bundles in the 2000 study cohort. Gleason score, percent tumor volume and perineural invasion were independently analyzed in the biopsy specimens according to the site of origin (right versus left side) for the 2001 group only. The ipsilateral neurovascular bundle was excised for Gleason 6 or less tumors when there were 50% or greater tumor volume in the biopsy specimen and perineural invasion, for Gleason 7 tumors when there was 30% or greater tumor volume, or perineural invasion and for Gleason 8 to 10 tumors when there was 10% or greater tumor volume, or perineural invasion. RESULTS: There were no statistically significant differences between the 2000 and 2001 groups in regard to preoperative prostate specific antigen, clinical and pathological stage, biopsy Gleason score and percent tumor volume in the surgical specimen. There was a statistically significant decrease in the incidence of positive margins between the 2000 and 2001 groups (14% versus 8%, p = 0.027). The lower positive margin rate was not achieved because of a tendency to excise more neurovascular bundles since a significantly greater percent of neurovascular bundles was preserved in the 2001 group. The sensitivity, specificity, positive and negative predictive values, and accuracy of our algorithm were 18%, 93%, 28%, 89% and 84%, respectively. In sides of the prostate with extraprostatic extension ipsilateral wide excision of the neurovascular bundle was associated with positive margins in 33% of cases compared with 22% when the neurovascular bundle was preserved (p = 0.42). CONCLUSIONS: The New York University nerve sparing algorithm prospectively defines when to excise the neurovascular bundle based on Gleason score, perineural invasion and tumor volume in the biopsy specimen. Use of this algorithm decreases positive surgical margin rates, while significantly increasing the preservation of neurovascular bundles.

Algorithms↗

PubMed2004

Sensitivity of an AIDS case-finding algorithm: who are we missing?

OBJECTIVE: The objective of this study was to determine the sensitivity of an AIDS case-finding algorithm. METHOD: This study applied the AIDS case-finding algorithm to paid Medicaid claims linked to New Jersey AIDS surveillance data and assesses its sensitivity across subgroups of patients. FINDINGS: Of the 7183 cases with confirmed AIDS, based on the state's registry information, 95% (n = 6818) were correctly detected using all Medicaid claims, including pharmacy. For patients in a community-based waiver program, covered by Medicare, diagnosed with a severe mental illness, or continuously enrolled in Medicaid, with regular contact with the medical system, the algorithm identified almost all patients. To further evaluate algorithm performance, it was used with 2 groups of interest to researchers. For AIDS patients in the last 6 months of life, 88% were correctly detected without use of pharmacy claims and 95% when pharmacy claims were included. For pregnant women, data from the 6 months before the latest delivery date identify 27% of pregnant women without pharmacy claims and 41% when pharmacy claims were included. Using claims made after the latest delivery date, 81% of pregnant women were detected without pharmacy claims and 93% when pharmacy claims were included CONCLUSION: Results demonstrate that a multilevel screen can be used with Medicaid claims to effectively to detect most patients with AIDS. Detection is lower for some subgroups, and the absence of pharmacy claims can compromise detection.

Acquired Immunodeficiency Syndrome↗