Phenomenological Constraints on the Transport Properties of QCD Matter with Data-Driven Model Averaging.

Using combined data from the Relativistic Heavy Ion and Large Hadron Colliders, we constrain the shear and bulk viscosities of quark-gluon plasma (QGP) at temperatures of ∼150-350 MeV. We use Bayesian inference to translate experimental and theoretical uncertainties into probabilistic constraints for the viscosities. With Bayesian model averaging we propagate an estimate of the model uncertainty generated by the transition from hydrodynamics to hadron transport in the plasma's final evolution stage, providing the most reliable phenomenological constraints to date on the QGP viscosities.

Determinants of high residual post-PCV13 pneumococcal vaccine-type carriage in Blantyre, Malawi: a modelling study.

BACKGROUND: In November 2011, Malawi introduced the 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant schedule. Four to 7 years after introduction (2015-2018), rolling prospective nasopharyngeal carriage surveys were performed in the city of Blantyre. Carriage of Streptococcus pneumoniae vaccine serotypes (VT) remained higher than reported in high-income countries, and impact was asymmetric across age groups. METHODS: A dynamic transmission model was fit to survey data using a Bayesian Markov-chain Monte Carlo approach, to obtain insights into the determinants of post-PCV13 age-specific VT carriage. RESULTS: Accumulation of naturally acquired immunity with age and age-specific transmission potential were both key to reproducing the observed data. VT carriage reduction peaked sequentially over time, earlier in younger and later in older age groups. Estimated vaccine efficacy (protection against carriage) was 66.87% (95% CI 50.49-82.26%), similar to previous estimates. Ten-year projected vaccine impact (VT carriage reduction) among 0-9 years old was lower than observed in other settings, at 76.23% (CI 95% 68.02-81.96%), with sensitivity analyses demonstrating this to be mainly driven by a high local force of infection. CONCLUSIONS: There are both vaccine-related and host-related determinants of post-PCV13 pneumococcal VT transmission in Blantyre with vaccine impact determined by an age-specific, local force of infection. These findings are likely to be generalisable to other Sub-Saharan African countries in which PCV impact on carriage (and therefore herd protection) has been lower than desired, and have implications for the interpretation of post-PCV carriage studies and future vaccination programs.

An Ultrathin Single Crystalline Relaxor Ferroelectric Integrated on a High Mobility Semiconductor.

The epitaxial growth of multifunctional oxides on semiconductors has opened a pathway to introduce new functionalities to semiconductor device technologies. In particular, the integration of gate materials that enable nonvolatile or hysteretic functionality in field-effect transistors could lead to device technologies that consume less power or allow for novel modalities in computing. Here we present electrical characterization of ultrathin single crystalline SrZrxTi1-xO3 (x = 0.7) films epitaxially grown on a high mobility semiconductor, Ge. Epitaxial films of SrZrxTi1-xO3 exhibit relaxor behavior, characterized by a hysteretic polarization that can modulate the surface potential of Ge. We find that gate layers as thin as 5 nm corresponding to an equivalent-oxide thickness of just 1.0 nm exhibit a ∼2 V hysteretic window in the capacitance-voltage characteristics. The development of hysteretic metal-oxide-semiconductor capacitors with nanoscale gate thicknesses opens new vistas for nanoelectronic devices.

Anticardiolipin antibodies and lupus anticoagulants among women undergoing in vitro fertilization in Jamaica.

OBJECTIVE: The aims of this study were to evaluate the effect of anticardiolipin antibody (aCL) and lupus anticoagulant (LA) on the outcome of the in vitro ferlitization (IVF) cycles and to determine the prevalence of these antibodies in infertile women seeking IVF in Jamaica. METHODS: A retrospective cohort study was performed to determine if screening patients for aCL and LA had any significant impact on the outcome of the IVF process. Each patients hospital record, between March 2000 and March 2010, was collected and the relevant data extracted. RESULTS: The prevalence of aCL in this cohort of Jamaican women was moderate/high positive 3.88%, low positive 0.68% and those with negative aCL results 95.4%. The prevalence of women who were LA positive was 4.1% and 0.9% of the women were positive for both LA and aCL. Of the patients who were LA and/or aCL positive, eight out of 30 patients (26.7%) had a positive pregnancy test in comparison to 61 out of 181 patients (33.7%) who were LA and/or aCL negative (p = 0.5787). CONCLUSION: The prevalence of positive aCL and/or LA in infertile women seeking IVF in Jamaica is 7.76%. The presence of these antibodies did not affect the pregnancy rate of these women nor did it demonstrate an increased risk for IVF cycle cancellation or ovarian hyperstimulation syndrome. Screening women undergoing IVF for these antibodies is not justified.

Successful treatment of severe male factor infertility in Jamaica with intracytoplasmic sperm injection.

OBJECTIVE: To examine the impact of intracytoplasmic sperm injection (ICSI) on the treatment of subfertile couples in Jamaica. METHOD: A review of the outcome of treatment cycles for infertile couples that underwent in-vitro fertilisation (IVF) and ICSI from 2003-05 at the Hugh Wynter Fertility Management Unit (HWFMU) of the University of the West Indies. Fertilisation and pregnancy rates for the cycles as well as the factors determining the success of the procedure were reviewed. SPSS 11.1 was used to do statistical calculations. RESULTS: Ninety-six ICSI cycles were done from January 1, 2003 to December 31, 2005. For couples with previous poor or no fertilisation in a standard IVF group (n = 12), the fertilisation rate was 72%; for those with substandard semen (n = 73), the fertilisation rate was 77.5%, for those with semen retrieved by surgical sperm method (n = 11), the fertilisation rate was 59%. The resulting live births were 0%, 12.5% and 27.3% respectively. There was a statistically significant impact of age on pregnancy rates as the mean age of the females in the previously poor or no fertilisation in a standard IVF group (39.08 +/- 5.14) was greater than those of the substandard semen group (35.93 +/- 4.22) [p = 0.023] as well as the group with surgical sperm retrieval (32.82 +/- 6.65) [p = 0.019]. CONCLUSION: With ICSI, the fertilisation and pregnancy rates in Jamaica are comparable to international rates regardless of the cause of infertility. However, the age of the female partner does have a significant impact on the pregnancy rate following ICSI.

Exercise peripheral oxygen saturation (SpO2) accurately reflects arterial oxygen saturation (SaO2) and predicts mortality in systemic sclerosis.

BACKGROUND: Measures of oxygenation have not been assessed for prognostic significance in systemic sclerosis-related interstitial lung disease (SSc-ILD). METHODS: 83 subjects with SSc-ILD performed a maximal cardiopulmonary exercise test with an arterial line. The agreement between peripheral oxygen saturation (SpO2) and arterial oxygen saturation (SaO2) was examined and survival differences between subgroups of subjects stratified on SpO2 were analysed. Cox proportional hazards analyses were used to examine the prognostic capabilities of SpO2. RESULTS: At maximal exercise the mean (SD) difference between SpO2 and SaO2 was 2.98 (2.98) and only 15 subjects had a difference of >4 points. The survival of subjects with SSc-ILD whose maximum exercise SpO2 (Spo(2)max) fell below 89% or whose SpO2max fell >4 points from baseline was worse than subjects in comparator groups (log rank p = 0.01 and 0.01, respectively). The hazard of death during the median 7.1 years of follow-up was 2.4 times greater for subjects whose SpO2max fell below 89% (hazard ratio 2.4, 95% CI 1.1 to 4.9, p = 0.02) or whose SpO2max fell >4 points from baseline (hazard ratio 2.4, 95% CI 1.1 to 5.0, p = 0.02). CONCLUSION: In patients with SSc-ILD, SpO2 is an adequate reflection of SaO2 and radial arterial lines need not be inserted during cardiopulmonary exercise tests in these patients. Given the ease of measurement and its prognostic value, SpO2 should be considered as a meaningful clinical and research outcome in patients with SSc-ILD.

Bacterial vaginosis in female facility workers in north-western Tanzania: prevalence and risk factors.

OBJECTIVES: To determine prevalence of, and risk factors for, bacterial vaginosis (BV) among herpes simplex virus (HSV) 2 seropositive Tanzanian women at enrollment into a randomised, placebo-controlled trial of HSV suppressive treatment. METHODS: 1305 HSV-2 seropositive women aged 16-35 years working in bars, guesthouses and similar facilities were interviewed, examined and tested for HIV, syphilis, Neisseria gonorrhoeae, Chlamydia trachomatis, BV, candidiasis and trichomoniasis. Factors associated with BV were analysed using logistic regression to estimate odds ratios and 95% confidence intervals. RESULTS: BV prevalence was 62.9%; prevalence of Nugent score 9-10 was 16.1%. Independent risk factors for BV were work facility type, fewer dependents, increasing alcohol consumption, sex in the last week (adjusted OR 2.03; 95% CI 1.57 to 2.62), using cloths or cotton wool for menstrual hygiene, HIV (adjusted OR 1.41; 95% CI 1.09 to 1.83) and Trichomonas vaginalis infection. There was no association between BV and the frequency or method of vaginal cleansing. However, BV was less prevalent among women who reported inserting substances to dry the vagina for sex (adjusted OR 0.44; 95% CI 0.25 to 0.75). CONCLUSION: BV was extremely prevalent among our study population of HSV-2 positive female facility workers in North-western Tanzania. Although recent sex was associated with increased BV prevalence, vaginal drying was associated with lower BV prevalence. Further studies of the effects of specific practices on vaginal flora are warranted.

Neuroleptic-induced decrease in plasma homovanillic acid and antipsychotic activity in schizophrenic patients.

Plasma-free homovanillic acid, a major metabolite of dopamine, was measured in chronically ill schizophrenic patients both before and during treatment with the antipsychotic phenothiazine, fluphenazine. Neuroleptic treatment was associated with a significant time-dependent decrease in plasma homovanillic acid from pretreatment values, which were significantly elevated when compared with those of age- and sex-matched healthy control subjects. Further, both the absolute concentrations as well as the neuroleptic-induced reductions in plasma homovanillic acid determined over 5 weeks of neuroleptic treatment were statistically significantly correlated with ratings of psychosis and improvement in psychosis, respectively. These findings suggest that the delayed effects of neuroleptic agents on presynaptic dopamine activity may more closely parallel their therapeutic actions than do their immediate effects in blocking postsynaptic dopamine receptors and that a decrease in dopamine "turnover" may be responsible for their antipsychotic effects.

Polarization-dependent electric potential distribution across nanoscale ferroelectric Hf0.5Zr0.5O2 in functional memory capacitors.

The emergence of ferroelectricity in nanometer-thick films of doped hafnium oxide (HfO2) makes this material a promising candidate for use in Si-compatible non-volatile memory devices. The switchable polarization of ferroelectric HfO2 controls functional properties of these devices through the electric potential distribution across the capacitor. The experimental characterization of the local electric potential at the nanoscale has not so far been realized in practice. Here, we develop a new methodology which allows us, for the first time, to experimentally quantify the polarization-dependent potential profile across few-nanometer-thick ferroelectric Hf0.5Zr0.5O2 thin films. Using a standing-wave excitation mode in synchrotron based hard X-ray photoemission spectroscopy, we depth-selectively probe TiN/Hf0.5Zr0.5O2/W prototype memory capacitors and determine the local electrostatic potential by analyzing the core-level line shifts. We find that the electric potential profile across the Hf0.5Zr0.5O2 layer is non-linear and changes with in situ polarization switching. Combined with our scanning transmission electron microscopy data and theoretical modeling, we interpret the observed non-linear potential behavior in terms of defects in Hf0.5Zr0.5O2, at both interfaces, and their charge state modulated by the ferroelectric polarization. Our results provide an important insight into the intrinsic electronic properties of HfO2 based ferroelectric capacitors and are essential for engineering memory devices.

Determinants of adiponectin levels in young people with Type 1 diabetes.

AIMS: To determine whether adiponectin levels are higher in youth with Type 1 diabetes than in non-diabetic controls, and explore potential determinants for this difference. METHODS: Data are from the SEARCH for Diabetes in Youth Case-Control Study. A total of 440 youth with Type 1 diabetes and 191 non-diabetic healthy controls age 10-22 years of non-Hispanic White (NHW), African-American (AA) and Hispanic (H) origin were included in this analysis. Mean adiponectin levels were compared between persons with diabetes and controls within each racial/ethnic group, sequentially adjusting for the following variables: demographic (age, sex, Tanner stage), kidney function (albumin: creatinin ratio: ACR), obesity (body mass index: BMI; waist circumference), behavioral (percent calories from fat, physical activity), and glucose control (hemoglobin A1c: HbA(1c)). RESULTS: Mean adiponectin levels, adjusted for age, sex and Tanner stage, were higher in persons with Type 1 diabetes than in control subjects, among NHW (17.6 vs 13.0 microg/ml, P < 0.001) and H (17.2 vs 13.0, P = 0.01), and slightly higher but not significantly so among AA (14.5 vs 12.6, P = 0.1). The differences persisted after additionally adjusting for differences in ACR, BMI and waist circumference. We found a positive relationship between adiponectin and HbA(1c) in youth with Type 1 diabetes, even after adjustment for age, sex and race/ethnicity. CONCLUSIONS: Adiponectin is higher in an ethnically diverse group of youth with Type 1 diabetes than in control subjects. The relationship between glycemic control and adiponectin in Type 1 diabetes requires further exploration.

Direct and possible indirect effects of vaccination on rotavirus hospitalisations among children in Malawi four years after programmatic introduction.

INTRODUCTION: Despite increased use of vaccine in routine immunisation, rotavirus remains a major cause of acute gastroenteritis (AGE) in low-income countries. We describe rotavirus prevalence and hospitalisation in Malawi pre and four years post vaccine introduction; provide updated vaccine effectiveness (VE) estimates; and assess rotavirus vaccine indirect effects. METHODS: Children under five years of age presenting to a referral hospital in Blantyre with AGE were recruited. Stool samples were tested for rotavirus using Enzyme Immunoassay. The change in rotavirus prevalence was evaluated using Poisson regression. Time series analysis was used to further investigate trends in prevalence over time. VE against rotavirus diarrhoea of any severity was estimated using logistic regression. Indirect effects were estimated by evaluating rotavirus prevalence in unvaccinated children over time, and by comparing observed reductions in incidence of rotavirus hospitalisation to those expected based on vaccine coverage and trial efficacy estimates. RESULTS: 2320 children were included. Prevalence of rotavirus in hospitalised infants (<12 months) with AGE decreased from 69/139(49.64%) prior to vaccine introduction to 197/607(32.45%) post-vaccine introduction (adjusted RR 0.67[95% CI 0.55, 0.82]). Prevalence in children aged 12-23 months demonstrated a less substantial decline: 15/37(40.54%) pre- and 122/352(34.66%) post-vaccine introduction (adjusted RR 0.85, 95% CI 0.57, 1.28). Adjusted VE was 61.89%(95% CI 28.04-79.82), but lower in children aged 12-23 months (31.69% [95% CI -139.03 to 80.48]). In hospitalised infants with rotavirus disease, the observed overall effect of the vaccine was 9% greater than expected according to vaccine coverage and efficacy estimates. Rotavirus prevalence among unvaccinated infants declined post-vaccine introduction (RR 0.70[95% CI 0.55-0.80]). CONCLUSIONS: Following rotavirus vaccine introduction in Malawi, prevalence of rotavirus in hospitalised children with AGE has declined significantly, with some evidence of an indirect effect in infants. Despite this, rotavirus remains an important cause of severe diarrhoea in Malawian children, particularly in the second year of life.

Structure of Ultrathin Native Oxides on III-Nitride Surfaces.

When pristine material surfaces are exposed to air, highly reactive broken bonds can promote the formation of surface oxides with structures and properties differing greatly from bulk. Determination of the oxide structure is often elusive through the use of indirect diffraction methods or techniques that probe only the outermost layer. As a result, surface oxides forming on widely used materials, such as group III-nitrides, have not been unambiguously resolved, even though critical properties can depend sensitively on their presence. In this study, aberration corrected scanning transmission electron microscopy reveals directly, and with depth dependence, the structure of ultrathin native oxides that form on AlN and GaN surfaces. Through atomic resolution imaging and spectroscopy, we show that the oxide layers are comprised of tetrahedra-octahedra cation-oxygen units, in an arrangement similar to bulk θ-Al2O3 and ß-Ga2O3. By applying density functional theory, we show that the observed structures are more stable than previously proposed surface oxide models. We place the impact of these observations in the context of key III-nitride growth, device issues, and the recent discovery of two-dimensional nitrides.

OSIRIS-REx Contamination Control Strategy and Implementation.

OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and <180 ng/cm2 of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance. Contamination is further characterized via witness material exposed to the spacecraft assembly and testing environment as well as in space. This characterization provided knowledge of the expected background and will be used in conjunction with archived spacecraft components for comparison with the samples when they are delivered to Earth for analysis. Most of all, the cleanliness of the OSIRIS-REx spacecraft was achieved through communication among scientists, engineers, managers, and technicians.

Lymphoblastic leukemia/lymphoma in mice overexpressing the Mer (MerTK) receptor tyrosine kinase.

Mer (MerTK) is a receptor tyrosine kinase important in platelet aggregation, as well as macrophage cytokine secretion and clearance of apoptotic cells. Mer is not normally expressed in thymocytes or lymphocytes; however, ectopic Mer RNA transcript and protein expression is found in a subset of acute lymphoblastic leukemia cell lines and patient samples, suggesting a role in leukemogenesis. To investigate the oncogenic potential of Mer in vivo, we created a transgenic mouse line (Mer(Tg)) that expresses Mer in the hematopoietic lineage under control of the Vav promoter. Ectopic expression and activation of the transgenic Mer protein was demonstrated in lymphocytes and thymocytes of the Mer(Tg) mice. At 12-24 months of age, greater than 55% of the Mer(Tg) mice, compared to 12% of the wild type, developed adenopathy, hepatosplenomegaly, and circulating lymphoblasts. Histopathological analysis and flow cytometry were consistent with T-cell lymphoblastic leukemia/lymphoma. Mer may contribute to leukemogenesis by activation of Akt and ERK1/2 anti-apoptotic signals, which were upregulated in Mer(Tg) mice. Additionally, a significant survival advantage was noted in Mer(Tg) lymphocytes compared to wild-type lymphocytes after dexamethasone treatment. These data suggest that Mer plays a cooperative role in leukemogenesis and may be an effective target for biologically based leukemia/lymphoma therapy.

Hyperprolactinaemia as an adverse effect in regulatory and clinical toxicology: role in breast and prostate cancer.

Historically, hyperprolactinaemia has been considered of low toxicological relevance when detected in toxicity studies, and even mammary carcinogenesis induced in the rat by prolactin excess has been considered of no relevance to humans. However, recent findings from human epidemiology and molecular biology suggests that prolactin is a risk factor for human breast cancer, and probably prostate cancer. Therefore, this new evidence should be considered in the various decisions to develop and license a new drug or chemical if the compound causes hyperprolactinaemia. This emerging evidence suggests that prolactin can also be produced locally from human breast cancer cells, and that, regardless of source (ie, pituitary or autocrine/paracrine production from cancer cells), prolactin is mitogenic, stimulates proliferation and suppresses apoptosis in breast and prostate cancer cells. This review outlines the evidence that hyperprolactinaemia should be considered a toxicological adverse effect and concludes that prolactin-induced rodent mammary carcinogenesis is relevant to humans and is not species-specific. The effects of prolactin on the prostate gland are also discussed; hyperprolactinaemia may be an additional risk factor for prostate cancer and this also requires consideration in toxicological risk assessments. The implications of increased prolactin secretion as an adverse effect for regulatory toxicology of drugs and chemicals, and in high risk patients receiving therapeutic drugs with hyperprolactinaemic side effects, is discussed. Alteration of prolactin level is also a novel mechanism that requires consideration in endocrine disruption research, since both endogenous oestrogens and also xenoestrogens stimulate prolactin secretion or affect prolactin receptors.

Gender differences in coping with infertility among couples undergoing counselling for In Vitro Fertilization treatment.

OBJECTIVE: To identify gender differences in coping responses and the association between coping and psychological distress in couples undergoing In Vitro Fertilization (IVF) treatment at the University of the West Indies (UWI). METHODS: All men and women (n = 52) who were offered psychological counselling prior to beginning IVF treatment between October 2003 and May 2004 were invited to complete questionnaires on their coping responses, self-reported distress and socio-demographic data. One female declined. RESULTS: Of the 51 participants, 52% had completed secondary education, 44% tertiary education, and 37% were 38 years or older; 42% of the couples were trying for more than seven years to have a child. Gender differences in coping included more women than men keeping others from knowing their pain (p < 0.01) and more women ruminating about what they did wrong to cause the infertility (p < 0.01). These strategies were also associated with reports of heightened distress (p < 0.05). Talking to others to obtain information was associated with less negative feelings. Coping skills that were commonly used by both genders included seeking medical advice and engaging in wishful thinking. CONCLUSION: Women coping with infertility may be at risk for self-depreciation and isolation because of their choice of coping strategies and the meaning they ascribe to the infertility. As a result, they are likely to experience more heightened distress than men who are also infertile. Counselling that is specific to gender-needs is indicated.

Copper Antimonide Nanowire Array Lithium Ion Anodes Stabilized by Electrolyte Additives.

Nanowires of electrochemically active electrode materials for lithium ion batteries represent a unique system that allows for intensive investigations of surface phenomena. In particular, highly ordered nanowire arrays produced by electrodeposition into anodic aluminum oxide templates can lead to new insights into a material's electrochemical performance by providing a high-surface-area electrode with negligible volume expansion induced pulverization. Here we show that for the Li-CuxSb ternary system, stabilizing the surface chemistry is the most critical factor for promoting long electrode life. The resulting solid electrolyte interphase is analyzed using a mix of electron microscopy, X-ray photoelectron spectroscopy, and lithium ion battery half-cell testing to provide a better understanding of the importance of electrolyte composition on this multicomponent alloy anode material.

The Impact of Landscape Complexity on Invertebrate Diversity in Edges and Fields in an Agricultural Area.

Invertebrate diversity is important for a multitude of ecosystem services and as a component of the larger ecological food web. A better understanding of the factors influencing invertebrate taxonomic richness and diversity at both local and landscape scales is important for conserving biodiversity within the agricultural landscape. The aim of this study was to determine if invertebrate richness and diversity in agricultural field interiors and edges in central Illinois, USA, were related to the complexity of the surrounding landscape. Our results show taxonomic richness and diversity in field edges is positively related to large scale landscape complexity, but the relationship is negative for field interiors. These unexpected results need further study.

Platelet tritiated imipramine binding and serotonin uptake in depressed patients and controls. Relationship to plasma cortisol levels before and after dexamethasone administration.

We measured platelet tritiated imipramine binding and serotonin uptake in 51 depressed patients and 43 normal controls. Although there were no significant differences in platelet 3H-imipramine binding or serotonin uptake when the total group of depressed patients was compared with controls, depressed women (n = 32) had a significantly lower maximal density of 3H-imipramine binding sites (beta max) than control women (n = 25). Moreover, among the total group of depressed patients, there were significant negative correlations between the beta max values and plasma cortisol levels at 4 PM (n = 41) and 11 PM (n = 41) following dexamethasone administration. These negative correlations between beta max and cortisol levels were strongest among melancholic patients both at 4 PM before dexamethasone administration (n = 14) and at 11 PM after dexamethasone administration (n = 15). These data suggest that the reported decrease in beta max found among depressed patients may be related to and is perhaps secondary to the hypercortisolemia of depression.

Discrepancies between patient recall and the medical record. Potential impact on diagnosis and clinical assessment of chronic disease.

BACKGROUND: During a case-control study, data necessary for fulfilling diagnostic and classification criteria for spondyloarthropathy were collected from 121 patients. OBJECTIVE: To study the potential impact of differences between patient recall and the medical record on diagnosis and clinical characterization of spondyloarthropathy as a model of chronic disease. METHODS: The study was conducted among four Alaskan Eskimo populations served by the Alaska Native Health Service. Two sets of historical data were compiled for each subject, one acquired during the interview and the other derived from the medical record. Paired items from the interview and the medical record were analyzed to determine discrepancies and consequent effects on diagnosis, classification, and disease characterization. RESULTS: Significant differences were observed in the reporting of genitourinary or diarrheal illnesses preceding or associated with arthritis, the occurrence of eye inflammation in association with joint pain, the occurrence of joint pain and back pain together, and the age at onset of back pain all of which are important to the diagnosis and classification of spondyloarthropathy. In contrast, for information needed to establish the probable inflammatory nature of back pain, patient interview was more helpful than the medical records, which did not provide adequate details to differentiate inflammatory from mechanical back pain. CONCLUSIONS: Patient recall bias can substantially affect diagnosis and clinical assessment of chronic disease, as exemplified by spondyloarthropathy. Reliance on records alone, however, may lead to underestimation of features that require subjective appraisal by the patient.