Mothers' and fathers' depressive symptoms across four years postpartum: An examination of between- and bidirectional within-person relations.

BACKGROUND: Both mothers and fathers are at risk for experiencing postpartum depressive symptoms shortly after the birth of a child. Previous studies suggest mothers' and fathers' depressive symptoms to be interrelated. This study examined bidirectional relations between mothers' and fathers' depressive symptoms across four years postpartum. METHODS: Longitudinal data for this study were collected across five waves from 485 mothers and 359 fathers of infants when infants were on average 6 months-old until children were 54 months-old (1-year lags). Mothers and fathers reported on their depressive symptoms using the Center for the Epidemiological Studies Short Depression Scale (CES-D 10). A random intercept cross-lagged panel model (RICLPM) was specified to examine the bidirectional relations between mothers' and fathers' depressive symptoms over time. RESULTS: At the between-person level, mothers' and fathers' depressive symptoms were positively associated. At the within-person level, unique carry-over effects were found for mothers and fathers in that when reporting higher depressive symptoms than their trait levels, they were more likely to report higher depressive symptoms one year later. Moreover, intermittent cross-lagged effects were observed from mothers' depressive symptoms to fathers' depressive symptoms during toddlerhood. LIMITATIONS: The sample was not racially or structurally diverse thereby limiting the generalizations of the findings. CONCLUSIONS: After the birth of a child, mothers and fathers are at risk for experiencing chronic depressive symptoms which can have implications for individual, couple and child health. Mothers' depressive symptoms are related to fathers' depressive symptoms over time.

"I'll Walk with You": LGBTQ+ Individuals and Religious Belonging.

Research on LGBTQ+ individuals, belonging, and religiosity has been mixed. Some studies have illustrated the ways religion can harm LGBTQ+ individuals while others suggest religion has positive impacts. In the current study, we sought to understand this complexity by examining the experiences of LGBTQ+ individuals who have been or currently are affiliated with The Church of Jesus Christ of Latter-day Saints (i.e. Mormon, LDS). A thematic analysis of 100 interviews with LGBTQ+ individuals currently or previously affiliated with the Church revealed various ways they feel belonging or the lack thereof in Latter-day Saint congregations and communities. These include sharing physical space, being invited to and included at events, receiving gifts or acts of service, seeing others' safety signals, hearing accepting and character-affirming language, and having others listen to them and give them voice. With the intent of fostering belonging, we discuss implications of this research for church communities and propose the belonging in practice: LGBTQ+ and religion model.

Masters of Media: A longitudinal study of parental media efficacy, media monitoring, and child problematic media use across early childhood in the United States.

The development of problematic media use in early childhood is not well understood. The current study examined long-term associations between parental media efficacy, parental media monitoring, and problematic media use across a three-year period of time during early childhood. Participants included 432 parents who reported on their own parenting and their child's use of problematic media once a year for three years (M age of child at Wave 1 = 29.68 months, SD = 3.73 months). Results revealed that early parental media efficacy predicted lower levels of child problematic media use over time. Restrictive media monitoring was also related to lower levels of child problematic media use over time. Additionally, general parental efficacy was related to parental media efficacy and lower child problematic media use, both at the cross-sectional and longitudinal levels. Discussion focuses on encouraging early parental media efficacy (and exploring other potential mechanisms) as a way to mitigate the development of problematic media use over time.

Analysis of Social Media Use, Mental Health, and Gender Identity Among US Youths.

Importance: Mental health among children and adolescents is a critical public health issue, and transgender and gender nonbinary youths are at an even greater risk. Social media has been consistently associated with youth mental health, but little is known about how gender identity interacts with this association. Objective: To use a risk and resilience approach to examine the association between social media use and mental health among transgender, gender nonbinary, and cisgender youths. Design, Setting, and Participants: This cross-sectional study analyzed data collected from an online survey between May and August 2021. Participants included a random sample of US youths; eligibility requirements included being aged 10 to 17 years and residing in the US. Statistical analysis was performed from February to April 2022. Main Outcomes and Measures: Social media use (time, type of use, favorite site, social comparisons, mindfulness, taking intentional breaks, cleaning and curating feeds, problematic use, and media literacy programs at their school) and mental health (depression, emotional problems, conduct problems, and body image) as main outcomes. Results: Participants included 1231 youths aged 10 to 17 years from a national quota sample from the United States; 675 (54.8%) identified as cisgender female, 479 (38.9%) as cisgender male, and 77 (6.3%) as transgender, gender nonbinary, or other; 4 (0.3%) identified as American Indian or Alaska Native, 111 (9.0%) as Asian, 185 (15.0%) as Black, 186 (15.1%) as Hispanic or Latinx, 1 (0.1%) as Pacific Islander, 703 (57.1%) as White, and 41 (3.3%) as mixed and/or another race or ethnicity. Gender identity moderated both the strength and the direction of multiple associations between social media practices and mental health: active social media use (eg, emotional problems: B = 1.82; 95% CI, 0.16 to 3.49; P = .03), cleaning and/or curating social media feeds (eg, depression: B = -0.91; 95% CI, -1.98 to -0.09; P = .03), and taking intentional breaks (eg, depression: B = 1.03; 95% CI, 0.14 to 1.92; P = .02). Conclusions and Relevance: In this cross-sectional study of gender identity, social media, and mental health, gender identity was associated with youths' experiences of social media in ways that may have distinct implications for mental health. These results suggest that research about social media effects on youths should attend to gender identity; directing children and adolescents to spend less time on social media may backfire for those transgender and gender nonbinary youths who are intentional about creating safe spaces on social media that may not exist in their offline world.

Validation of the Kinetik Blood Pressure Monitor-Series 1 for use in adults at home and in clinical settings, according to the 2002 European Society of Hypertension International Protocol on the validation of blood pressure devices.

The aim of this study was to assess the blood pressure (BP) measurement accuracy of the Kinetik Blood Pressure Monitor-Series 1 (BPM-1) for use in home or clinical settings according to the 2002 European Society of Hypertension International Protocol (ESH-IP). Forty-two participants were recruited to fulfil the required number of systolic and diastolic BP measurements according to the ESH-IP. Nine sequential same-arm BP readings were measured and analysed for each participant using the test device and observer mercury standard readings according to the 2002 ESH-IP. Forty one participants were used to obtain 33 sets of systolic and diastolic BP readings and were included in the analysis. Mean difference between the device measurements and the observer (mercury standard) measurements was 1.1 ± 7.2/1.1 ± 6.8 mmHg (mean ± standard deviation; systolic/diastolic). The number of systolic BP differences between the test and observer measurements that fell within 5, 10 and 15 mmHg was 65, 86 and 92. For diastolic readings, the number of test-observer measurement differences within 5, 10 and 15 mmHg was 77, 91 and 94. The number of participants with at least two out of three differences within 5 mmHg was 28 for systolic and 40 for diastolic BP readings. Three participants had no differences between the test and observer measurements within 5 mmHg in both the systolic and diastolic measurement categories. The Kinetik BPM-1 device fulfilled the requirements of the ESH-IP validation procedure and can be recommended for clinical use and self-measurement within the home.

Self-monitoring of Blood Pressure in Patients With Hypertension-Related Multi-morbidity: Systematic Review and Individual Patient Data Meta-analysis.

BACKGROUND: Studies have shown that self-monitoring of blood pressure (BP) is effective when combined with co-interventions, but its efficacy varies in the presence of some co-morbidities. This study examined whether self-monitoring can reduce clinic BP in patients with hypertension-related co-morbidity. METHODS: A systematic review was conducted of articles published in Medline, Embase, and the Cochrane Library up to January 2018. Randomized controlled trials of self-monitoring of BP were selected and individual patient data (IPD) were requested. Contributing studies were prospectively categorized by whether they examined a low/high-intensity co-intervention. Change in BP and likelihood of uncontrolled BP at 12 months were examined according to number and type of hypertension-related co-morbidity in a one-stage IPD meta-analysis. RESULTS: A total of 22 trials were eligible, 16 of which were able to provide IPD for the primary outcome, including 6,522 (89%) participants with follow-up data. Self-monitoring was associated with reduced clinic systolic BP compared to usual care at 12-month follow-up, regardless of the number of hypertension-related co-morbidities (-3.12 mm Hg, [95% confidence intervals -4.78, -1.46 mm Hg]; P value for interaction with number of morbidities = 0.260). Intense interventions were more effective than low-intensity interventions in patients with obesity (P < 0.001 for all outcomes), and possibly stroke (P < 0.004 for BP control outcome only), but this effect was not observed in patients with coronary heart disease, diabetes, or chronic kidney disease. CONCLUSIONS: Self-monitoring lowers BP regardless of the number of hypertension-related co-morbidities, but may only be effective in conditions such obesity or stroke when combined with high-intensity co-interventions.

Real world use of loteprednol etabonate ophthalmic gel 0.5% in cases representative of comorbid pathologies responding to minimally invasive glaucoma surgery.

PURPOSE: With the increasing use of minimally invasive surgical techniques for intraocular pressure (IOP) lowering in glaucoma patients, there is a need to examine best practices regarding the postoperative management of these patients. Corticosteroids, though effective in controlling postoperative ocular pain and inflammation, present distinct challenges in glaucoma surgery patients, as their use can be associated with IOP elevation. Loteprednol etabonate (LE) is an ocular corticosteroid designed to have an improved safety profile relative to other corticosteroids. METHODS: We report here a representative selection of cases in which patients were successfully treated with LE ophthalmic gel 0.5% (LE gel) following a variety of minimally invasive glaucoma surgery (MIGS) procedures. Cases included patients undergoing various procedures including a Trabectome combined with cataract surgery; micro-stent surgery (iStent) combined with cataract surgery; supraciliary CyPass Micro-Stent placement combined with cataract surgery; Kahook Dual Blade goniotomy; and ab interno canaloplasty using the iTrack catheter. OBSERVATIONS: In all cases, use of LE gel during the postoperative period appeared effective and safe in reducing inflammation and controlling pain. No adverse events or IOP elevations were noted, even in those patients continuing use of LE gel past the postoperative period for longer than six months with documented follow-up. In two cases, patients with elevated IOP using either prednisolone or difluprednate postoperatively were switched to LE gel, with a subsequent reduction in IOP. CONCLUSIONS: This selection of cases involving patients undergoing MIGS suggests that LE gel may be an effective and safe option for treating postoperative inflammation and pain following such procedures with minimal to no effect on IOP or other negative sequalae.

Understanding successful and unsuccessful landings of aerial maneuver variations in professional surfing.

Although performing aerial maneuvers can increase wave score and winning potential in competitive surfing, the critical features underlying successful aerial performance have not been systematically investigated. This study aimed to analyze highly skilled aerial maneuver performance and to identify the critical features associated with successful or unsuccessful landing. Using video recordings of the World Surf League's Championship Tour, every aerial performed during the quarterfinal, semifinal, and final heats from the 11 events in the 2015 season was viewed. From this, 121 aerials were identified with the Frontside Air (n = 15) and Frontside Air Reverse (n = 67) being selected to be qualitatively assessed. Using chi-squared analyses, a series of key critical features, including landing over the center of the surfboard (FS Air χ2  = 14.00, FS Air Reverse χ2  = 26.61; P < .001) and landing with the lead ankle in dorsiflexion (FS Air χ2  = 3.90, FS Air Reverse χ2  = 13.64; P < .05), were found to be associated with successful landings. These critical features help surfers land in a stable position, while maintaining contact with the surfboard. The results of this study provide coaches with evidence to adjust the technique of their athletes to improve their winning potential.

The Gopen-Yang Superior Semicircular Canal Dehiscence Questionnaire: development and validation of a clinical questionnaire to assess subjective symptoms in patients undergoing surgical repair of superior semicircular canal dehiscence.

OBJECTIVE: To characterise subjective symptoms in patients undergoing surgical repair of superior semicircular canal dehiscence. METHODS: Questionnaires assessing symptom severity and impact on function and quality of life were administered to patients before superior semicircular canal dehiscence surgery, between June 2011 and March 2016. Questionnaire sections included general quality of life, internal amplified sounds, dizziness and tinnitus, with scores of 0-100 points. RESULTS: Twenty-three patients completed the questionnaire before surgery. Section scores (mean±standard deviation) were: 38.2 ± 25.2 for general quality of life, 52.5 ± 23.9 for internal amplified sounds, 35.1 ± 28.8 for dizziness, 33.3 ± 30.7 for tinnitus, and 39.8 ± 22.2 for the composite score. Cronbach's α statistic averaged 0.93 (range, 0.84-0.97) across section scores, and 0.83 for the composite score. CONCLUSION: The Gopen-Yang Superior Semicircular Canal Dehiscence Questionnaire provides a holistic, patient-centred characterisation of superior semicircular canal dehiscence symptoms. Internal consistency analysis validated the questionnaire and provided a quantitative framework for further optimisation in the clinical setting.

Prevalence and predictors of hospital prealerting in acute stroke: a mixed methods study.

BACKGROUND: Thrombolysis can significantly reduce the burden of stroke but the time window for safe and effective treatment is short. In patients travelling to hospital via ambulance, the sending of a 'prealert' message can significantly improve the timeliness of treatment. OBJECTIVE: Examine the prevalence of hospital prealerting, the extent to which prealert protocols are followed and what factors influence emergency medical services (EMS) staff's decision to send a prealert. METHODS: Cohort study of patients admitted to two acute stroke units in West Midlands (UK) hospitals using linked data from hospital and EMS records. A logistic regression model examined the association between prealert eligibility and whether a prealert message was sent. In semistructured interviews, EMS staff were asked about their experiences of patients with suspected stroke. RESULTS: Of the 539 patients eligible for this study, 271 (51%) were recruited. Of these, only 79 (29%) were eligible for prealerting according to criteria set out in local protocols but 143 (53%) were prealerted. Increasing number of Face, Arm, Speech Test symptoms (1 symptom, OR 6.14, 95% CI 2.06 to 18.30, p=0.001; 2 symptoms, OR 31.36, 95% CI 9.91 to 99.24, p<0.001; 3 symptoms, OR 75.84, 95% CI 24.68 to 233.03, p<0.001) and EMS contact within 5 h of symptom onset (OR 2.99, 95% CI 1.37 to 6.50 p=0.006) were key predictors of prealerting but eligibility for prealert as a whole was not (OR 1.92, 95% CI 0.85 to 4.34 p=0.12). In qualitative interviews, EMS staff displayed varying understanding of prealert protocols and described frustration when their interpretation of the prealert criteria was not shared by ED staff. CONCLUSIONS: Up to half of the patients presenting with suspected stroke in this study were prealerted by EMS staff, regardless of eligibility, resulting in disagreements with ED staff during handover. Aligning the expectations of EMS and ED staff, perhaps through simplified prealert protocols, could be considered to facilitate more appropriate use of hospital prealerting in acute stroke.

Development of the microsporidian parasite, Loma salmonae, in a rainbow trout gill epithelial cell line (RTG-1): evidence of xenoma development in vitro.

Growth and propagation of fish-infecting microsporidians within cell culture has been more difficult to achieve than for insect- and human-infecting microsporidians. Fish microsporidia tend to elicit xenoma development rather than diffuse growth in vivo, and this process likely increases host specificity. We present evidence that the fish microsporidian, Loma salmonae, has the capacity to develop xenomas within a rainbow trout gill epithelial cell line (RTG-1). Spore numbers increased over a 4 weeks period within cell culture flasks. Xenoma-like structures were observed using phase contrast microscopy, and then confirmed using transmission electron microscopy. Optimization of the L. salmonae-RTG-1 cell model has important implications in elucidating the process of xenoma development induced by microsporidian parasites.

Anti-PF4/heparin antibodies and venous graft occlusion in postcoronary artery bypass surgery patients randomized to postoperative unfractionated heparin or fondaparinux thromboprophylaxis.

BACKGROUND: Anti-PF4/heparin antibodies are frequently generated after coronary artery bypass grafting (CABG) surgery, with platelet-activating IgG implicated in heparin-induced thrombocytopenia (HIT). It is controversial whether non-platelet-activating antibodies are associated with thrombosis. OBJECTIVES: To determine in post-CABG patients whether thromboprophylaxis using fondaparinux vs. unfractionated heparin (UFH) reduces the frequency of anti-PF4/heparin antibodies, and whether anti-PF4/heparin antibodies are associated with early graft occlusion. METHODS/PATIENTS: In a pre-planned secondary analysis of a randomized control trial (RCT) comparing fondaparinux vs. UFH thromboprophylaxis post-CABG, we determined the frequency of anti-PF4/heparin antibody formation by solid-phase enzyme-immunoassay (EIA) and of platelet-activating antibodies by serotonin-release assay (SRA); the SRA and fluid-phase EIA were used to assess fondaparinux cross-reactivity. We also examined whether anti-PF4/heparin antibodies were associated with early arterial or venous graft occlusion (6-week CT angiography). RESULTS: We found no significant difference in the frequency of antibody formation between patients who received fondaparinux vs. UFH (65.3% vs. 46.0%; P = 0.069), and no significant fondaparinux cross-reactivity. Venous graft occlusion(s) occurred in 6/26 patients who formed 'strong' IgG antibodies (≥ 1.0 optical density [OD] units and ≥ 2× baseline) vs. 3/66 who did not (P = 0.0139). In both unadjusted and adjusted analyses, strong postoperative (but not pre-operative) anti-PF4/heparin IgG responses were associated with a markedly increased risk of early venous (but not arterial) graft occlusion (adjusted OR, 9.25 [95% CI, 1.73, 49.43]; P = 0.0093); notably, none of the three SRA-positive patients developed a venous graft occlusion. CONCLUSIONS: Fondaparinux vs. UFH thromboprophylaxis postCABG does not reduce anti-PF4/heparin antibody formation. Non-platelet-activating anti-PF4/heparin IgG antibodies generated post operatively are associated with early venous graft occlusion.

Impact of age and sex on primary preventive treatment for cardiovascular disease in the West Midlands, UK: cross sectional study.

OBJECTIVES: To establish the impact of age and sex on primary preventive treatment for cardiovascular disease in a typical primary care population. DESIGN: Cross sectional study of anonymised patient records. PARTICIPANTS: All 41,250 records of patients aged ≥ 40 registered at 19 general practices in the West Midlands, United Kingdom, were extracted and analysed. MAIN OUTCOME MEASURES: Patients' demographics, risk factors for cardiovascular disease (blood pressure, total cholesterol concentration), and prescriptions for primary preventive drugs were extracted from patients' records. Patients were subdivided into five year age bands up to 85 (patients aged ≥ 85 were analysed as one group) and prescribing trends across the population were assessed by estimating the proportion of patients prescribed with antihypertensive drug or statin drug, or both, in each group. RESULTS: Of the 41,250 records screened in this study, 36,679 (89%) patients did not have a history of cardiovascular disease and therefore could be considered for primary preventive treatment. The proportion receiving antihypertensive drugs increased with age (from 5% (378/6978) aged 40-44 to 57% (621/1092) aged ≥ 85) as did the proportion taking statins up to the age of 74 (from 3% (201/6978) aged 40-44 to 29% (675/2367) aged 70-74). In those aged 75 and above, the odds of a receiving prescription for a statin (relative to the 40-44 age group) decreased with every five year increment in age (odds ratio 12.9 (95% confidence interval 10.8 to 15.3) at age 75-79 to 5.7 (4.6 to 7.2) at age ≥ 85; P<0.001). There were no consistent differences in prescribing trends by sex. CONCLUSIONS: Previously described undertreatment of women in secondary prevention of cardiovascular disease was not observed for primary prevention. Low use of statins in older people highlights the need for a stronger evidence base and clearer guidelines for people aged over 75.

Effects of altered estuarine submerged macrophyte bed cover on the omnivorous Cape stumpnose Rhabdosargus holubi.

The ecological importance of submerged macrophyte beds to fishes within estuaries was investigated through the example of the ubiquitous Cape stumpnose Rhabdosargus holubi, an omnivorous, vegetation and estuary-dependent species, using stable-isotope techniques and long-term abundance (catch-per-unit-effort) data from the East Kleinemonde Estuary, South Africa. Outputs from a Bayesian mixing model using δ(13) C and δ(15) N signatures indicated that the submerged macrophytes Ruppia cirrhosa and Potamogeton pectinatus were not a primary source of nutrition for R. holubi, confirming previous work that revealed that macrophytes are consumed but not digested. Long-term seine netting data showed reduced abundance of R. holubi during a prolonged period of macrophyte senescence, suggesting that submerged macrophyte habitats provide shelter that reduces mortality (predation risk) and a food-rich foraging area.

Fondaparinux treatment of acute heparin-induced thrombocytopenia confirmed by the serotonin-release assay: a 30-month, 16-patient case series.

BACKGROUND: Fondaparinux is theoretically an attractive agent for the treatment of immune heparin-induced thrombocytopenia (HIT), a prothrombotic disorder caused by platelet-activating anti-platelet factor 4/heparin antibodies. Although reports of the use of fondaparinux for this indication have thus far been favorable, the diagnosis of HIT in most cases was not based on definitive laboratory confirmation of heparin-dependent, platelet-activating antibodies. OBJECTIVES: To report thrombotic and major bleeding outcomes with fondaparinux in patients with a high likelihood of having acute HIT based on clinical features and a positive result in the confirmatory platelet serotonin-release assay (SRA), a sensitive and specific test for platelet-activating HIT antibodies. METHODS/PATIENTS: We reviewed consecutive eligible patients with SRA-positive HIT (mean peak serotonin release, 91% [normal, < 20%]; mean IgG-specific PF4/heparin enzyme immunoassay result, 2.53 optical density units [normal, < 0.45 units]) in one medical center over a 30-month period who received fondaparinux for anticoagulation during acute HIT (platelet count, < 150 × 10(9) L(-1)). Where available, plasma samples were used to measure thrombin-antithrombin (TAT) complex levels. RESULTS: Sixteen patients with SRA-positive HIT received fondaparinux: 14 surgical (11 after cardiac surgery; three after vascular surgery) and two medical (acute stroke). Fifty-six per cent of patients had HIT-associated thrombosis at the time of diagnosis. No patient developed new, recurrent or progressive thrombosis; one patient developed a major bleed (calf hematoma). One patient judged to have irreversible tissue necrosis before receiving fondaparinux therapy ultimately required limb amputation. TAT complex levels were reduced within 24 h of starting fondaparinux, and 13 of 13 patients were successfully switched to warfarin. CONCLUSION: Fondaparinux shows promise for the treatment of patients with SRA-positive acute HIT.

Warm-up affects diurnal variation in power output.

The purpose of this study was to examine whether time of day variations in power output can be accounted for by the diurnal fluctuations existent in body temperature. 8 recreationally trained males (29.8±5.2 yrs; 178.3±5.2 cm; 80.3±6.5 kg) were assessed on 4 occasions following a: (a) control warm-up at 8.00 am; (b) control warm-up at 4.00 pm; (c) extended warm-up at 8.00 am; and, (d) extended warm-up at 4.00 pm. The control warm-up consisted of dynamic exercises and practice jumps. The extended warm-up incorporated a 20 min general warm-up on a stationary bike prior to completion of the control warm-up, resulting in a whole body temperature increase of 0.3±0.2°C. Kinetic and kinematic variables were measured using a linear optical encoder attached to a barbell during 6 loaded counter-movement jumps. Results were 2-6% higher in the afternoon control condition than morning control condition. No substantial performance differences were observed between the extended morning condition and afternoon control condition where body temperatures were similar. Results indicate that diurnal variation in whole body temperature may explain diurnal performance differences in explosive power output and associated variables. It is suggested that warm-up protocols designed to increase body temperature are beneficial in reducing diurnal differences in jump performance.

Heparin-induced thrombocytopenia: towards standardization of platelet factor 4/heparin antigen tests.

BACKGROUND: Laboratory confirmation of heparin-induced thrombocytopenia (HIT) is based on detection of heparin-dependent platelet-activating antibodies. Platelet factor 4 (PF4)/heparin enzyme-immunoassays (EIA) are a widely available surrogate for platelet-activating antibodies. OBJECTIVE: Defining the optical density (OD) reactivity profiles of a PF4/heparin EIA in reference subject and patient populations and the correlation of the EIA results (expressed in OD units) with the prevalence of platelet-activating antibodies. PATIENTS/METHODS: Using quantile regression we determined the 97.5th percentile of PF4/heparin-immunoglobulin G (IgG) EIA reactivities in non-heparin-treated individuals [blood donors (n = 935)] and patients before heparin therapy (n = 1207). In patients with suspected HIT, we compared the correlation of EIA-IgG reactivities (Greifswald laboratory; n = 2821) and the heparin-induced platelet activation assay (HIPA) with the correlation of reactivities of another EIA-IgG (McMaster laboratory; n = 1956) with the serotonin-release assay (SRA). RESULTS: PF4/heparin-IgG EIA OD reactivities had a lower OD 97.5th percentile in blood donors compared with patient groups before heparin treatment (P < 0.001). The percentage of sera testing positive in the functional assays strongly correlated with PF4/heparin-IgG EIA OD reactivities in both laboratories with very similar results (correlation coefficient > 0.9) when normalized OD ranges (maximum OD divided by 10) were used instead of absolute OD values. CONCLUSIONS: Results of PF4/heparin-IgG EIA should not be reported as only positive or negative as there is no single acceptable cut-off value. Instead, reporting PF4/heparin-IgG EIA OD results in ranges allows for risk-stratified prediction for presence of platelet-activating antibodies. Use of normalized OD ranges permits a standardized approach for inter-laboratory comparisons.