Dataset Information

Simple estimation of incident HIV infection rates in notification cohorts based on window periods of algorithms for evaluation of line-immunoassay result patterns.

ABSTRACT:

Background

Tests for recent infections (TRIs) are important for HIV surveillance. We have shown that a patient's antibody pattern in a confirmatory line immunoassay (Inno-Lia) also yields information on time since infection. We have published algorithms which, with a certain sensitivity and specificity, distinguish between incident (< = 12 months) and older infection. In order to use these algorithms like other TRIs, i.e., based on their windows, we now determined their window periods.

Methods

We classified Inno-Lia results of 527 treatment-naïve patients with HIV-1 infection < = 12 months according to incidence by 25 algorithms. The time after which all infections were ruled older, i.e. the algorithm's window, was determined by linear regression of the proportion ruled incident in dependence of time since infection. Window-based incident infection rates (IIR) were determined utilizing the relationship 'Prevalence = Incidence x Duration' in four annual cohorts of HIV-1 notifications. Results were compared to performance-based IIR also derived from Inno-Lia results, but utilizing the relationship 'incident = true incident + false incident' and also to the IIR derived from the BED incidence assay.

Results

Window periods varied between 45.8 and 130.1 days and correlated well with the algorithms' diagnostic sensitivity (R(2) = 0.962; P<0.0001). Among the 25 algorithms, the mean window-based IIR among the 748 notifications of 2005/06 was 0.457 compared to 0.453 obtained for performance-based IIR with a model not correcting for selection bias. Evaluation of BED results using a window of 153 days yielded an IIR of 0.669. Window-based IIR and performance-based IIR increased by 22.4% and respectively 30.6% in 2008, while 2009 and 2010 showed a return to baseline for both methods.

Conclusions

IIR estimations by window- and performance-based evaluations of Inno-Lia algorithm results were similar and can be used together to assess IIR changes between annual HIV notification cohorts.

SUBMITTER: Schupbach J

PROVIDER: S-EPMC3753319 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

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Publications

Simple estimation of incident HIV infection rates in notification cohorts based on window periods of algorithms for evaluation of line-immunoassay result patterns.

Schüpbach Jörg J Gebhardt Martin D MD Scherrer Alexandra U AU Bisset Leslie R LR Niederhauser Christoph C Regenass Stephan S Yerly Sabine S Aubert Vincent V Suter Franziska F Pfister Stefan S Martinetti Gladys G Andreutti Corinne C Klimkait Thomas T Brandenberger Marcel M Günthard Huldrych F HF

PloS one 20130826 8

<h4>Background</h4>Tests for recent infections (TRIs) are important for HIV surveillance. We have shown that a patient's antibody pattern in a confirmatory line immunoassay (Inno-Lia) also yields information on time since infection. We have published algorithms which, with a certain sensitivity and specificity, distinguish between incident (< = 12 months) and older infection. In order to use these algorithms like other TRIs, i.e., based on their windows, we now determined their window periods.<h ...[more]

PMID: 23990968

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Project description:BackgroundSerologic testing algorithms for recent HIV seroconversion (STARHS) provide important information for HIV surveillance. We have previously demonstrated that a patient's antibody reaction pattern in a confirmatory line immunoassay (INNO-LIA™ HIV I/II Score) provides information on the duration of infection, which is unaffected by clinical, immunological and viral variables. In this report we have set out to determine the diagnostic performance of Inno-Lia algorithms for identifying incident infections in patients with known duration of infection and evaluated the algorithms in annual cohorts of HIV notifications.MethodsDiagnostic sensitivity was determined in 527 treatment-naive patients infected for up to 12 months. Specificity was determined in 740 patients infected for longer than 12 months. Plasma was tested by Inno-Lia and classified as either incident (< = 12 m) or older infection by 26 different algorithms. Incident infection rates (IIR) were calculated based on diagnostic sensitivity and specificity of each algorithm and the rule that the total of incident results is the sum of true-incident and false-incident results, which can be calculated by means of the pre-determined sensitivity and specificity.ResultsThe 10 best algorithms had a mean raw sensitivity of 59.4% and a mean specificity of 95.1%. Adjustment for overrepresentation of patients in the first quarter year of infection further reduced the sensitivity. In the preferred model, the mean adjusted sensitivity was 37.4%. Application of the 10 best algorithms to four annual cohorts of HIV-1 notifications totalling 2'595 patients yielded a mean IIR of 0.35 in 2005/6 (baseline) and of 0.45, 0.42 and 0.35 in 2008, 2009 and 2010, respectively. The increase between baseline and 2008 and the ensuing decreases were highly significant. Other adjustment models yielded different absolute IIR, although the relative changes between the cohorts were identical for all models.ConclusionsThe method can be used for comparing IIR in annual cohorts of HIV notifications. The use of several different algorithms in combination, each with its own sensitivity and specificity to detect incident infection, is advisable as this reduces the impact of individual imperfections stemming primarily from relatively low sensitivities and sampling bias.

Project description:ImportancePatients are increasingly being given access to their test results, but little is known about how preferences vary with the test under consideration or the results of the test (normal or abnormal).ObjectiveThis study was conducted to examine preferences for test result communication.Design, setting, and participantsWe surveyed adults to explore their preferences for test result notification for three common diagnostic tests of varying "emotional impact" (dual-energy x-ray absorptiometry [DXA], genital herpes, and cancer biopsy) when test results were 1) normal and 2) abnormal. We conducted our survey between June and August 2012 on the campus of an academic medical center. For each scenario, subjects were asked to rank seven methods that might be used to communicate test results (letter, unsecured email, secured email, text message, telephone call, secure Web portal, office visit) in order of acceptability.Main outcome measuresThe main measures were the percentage of respondents who ranked a particular test result notification method favorably and the percentage who ranked it as unacceptable.ResultsWhen test results were normal, subjects' notification preferences were generally similar for DXA, herpes and cancer biopsy, with telephone and letter ranked most favorably for all three tests. Conversely, text message and unsecured email were viewed as unacceptable notification methods for normal results by 45.0-55.0 % of subjects across all three tests. When test results were abnormal, office visits became more popular. A higher proportion of subjects ranked office visits as their most preferred notification method for our test with high "emotional impact" (cancer biopsy) (38.4 %) as compared to DXA (28.2 %) and herpes (27.9 %) (P = 0.02). For most test scenarios, younger subjects appeared to rank electronic communication modalities (secure email or Web portal) higher than older subjects, though this difference did not reach statistical significance (P = 0.29).ConclusionsPreferences for test result notification can differ substantially depending upon the test under consideration and results of the test. Providers and health care systems should consider these factors when deciding how to communicate results to patients.

Project description:Calcium and vitamin D intake and exercise are suboptimal among older adults. Following bone densitometry, a letter communicating individualized fracture risk accompanied by an educational brochure improved participants' lifestyle-but no more than existing communication strategies-over 52 weeks. Simple communication strategies are insufficient for achieving optimal levels of bone health behaviors. PURPOSE:The Patient Activation After DXA Result Notification (PAADRN) study was designed to evaluate whether a letter with individualized fracture risk and an educational brochure mailed to patients soon after their DXA might improve bone health behaviors (daily calcium intake, vitamin D supplementation, and weekly exercise sessions) compared to slower, less individualized communication characterizing usual care. METHODS:Participants ??50 years were recruited, at three sites, following their DXA and randomized with 1:1 allocation to intervention and control (usual care only) groups. Data were collected at enrollment interview and by phone survey at 12 and 52 weeks thereafter. Intention-to-treat analyses were conducted on 7749 of the 20,397 eligible participants who enrolled. Changes in bone health behaviors were compared within and between study groups. Average treatment effects and heterogeneity of treatment effects were estimated with multivariable linear and logistic regression models. RESULTS:In unadjusted analyses, calcium intake, vitamin D supplementation, and weekly exercise sessions increased significantly over 52 weeks within both the intervention and control groups (all p?<?0.001). In unadjusted analyses and multivariable models, increases in each behavior did not significantly differ between the intervention and control groups. Intervention group participants with a >?20% 10-year fracture risk at enrollment did, however, have a significantly greater increase in calcium intake compared to other study participants (p?=?0.031). CONCLUSIONS:Bone health behaviors improved, on average, over 52 weeks among all participants following a DXA. Receipt of the PAADRN letter and educational brochure did not directly improve bone health behaviors compared to usual care. TRIAL REGISTRATION:The Patient Activation after DXA Result Notification (PAADRN) Study is registered at ClinicalTrials.Gov: NCT01507662, https://clinicaltrials.gov/ct2/show/NCT01507662.

Dataset Information

Simple estimation of incident HIV infection rates in notification cohorts based on window periods of algorithms for evaluation of line-immunoassay result patterns.

Background

Methods

Results

Conclusions

Publications

Simple estimation of incident HIV infection rates in notification cohorts based on window periods of algorithms for evaluation of line-immunoassay result patterns.

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