Psychometric Properties of LUN-MS: A New Questionnaire to Identify the Unmet Needs of People With Multiple Sclerosis

Background

We developed a 29-item Questionnaire, Long-term Unmet Needs in MS (LUN-MS) to identify the unmet needs of people with multiple sclerosis (pwMS).

Objective

To assess acceptability, test-retest reliability, internal consistency, and validity of the LUN-MS.

Methods

Participants completed the LUN-MS and MSIS-29 twice, four weeks apart. Acceptability was assessed by looking at the response rate in each time point. Reliability was calculated by comparing the response during the two time points using Cohen's weighted kappa. Using principal component analysis, the dimensionality of the questionnaire's items was reduced, to five domains and the internal consistency of each domain was assessed using Cronbach's alpha. Concurrent validity was tested by comparing the total LUN-MS score against MSIS-29 and EQ-5D-3L using Pearson's product-moment correlation coefficient.

Results

Among 88 participants, rate of completion at time points-1 and 2 was 96 and 80% respectively. Test-retest reliability for individual items was between fair to near-perfect (weighted Cohen's kappa 0.39-0.81). The unmet needs could be divided into five internally consistent domains (Cronbach's alpha 0.83-0.74): neuropsychological, ambulation, physical, interpersonal relationship and informational. Concurrent validity with MSIS-29 (r = 0.705, P < .001) and EQ-5D-3L (r = 0.617, P < .001) were good.

Conclusion

LUN-MS is a reliable, valid, and acceptable tool to identify the unmet needs of pwMS.

Analysis of brain and spinal MRI measures in a common domain to investigate directional neurodegeneration in motor neuron disease

BACKGROUND

Magnetic resonance imaging (MRI) of the brain and cervical spinal cord is often performed in diagnostic evaluation of suspected motor neuron disease/amyotrophic lateral sclerosis (MND/ALS). Analysis of MRI-derived tissue damage metrics in a common domain facilitates group-level inferences on pathophysiology. This approach was applied to address competing hypotheses of directionality of neurodegeneration, whether anterograde, cranio-caudal dying-forward from precentral gyrus or retrograde, dying-back.

METHODS

In this cross-sectional study, MRI was performed on 75 MND patients and 13 healthy controls. Precentral gyral thickness was estimated from volumetric T1-weighted images using FreeSurfer, corticospinal tract fractional anisotropy (FA) from diffusion tensor imaging using FSL, and cross-sectional cervical cord area between C1-C8 levels using Spinal Cord Toolbox. To analyse these multimodal data within a common domain, individual parameter estimates representing tissue damage at each corticospinal tract level were first converted to z-scores, referenced to healthy control norms. Mixed-effects linear regression models were then fitted to these z-scores, with gradients hypothesised to represent directionality of neurodegeneration.

RESULTS

At group-level, z-scores did not differ significantly between precentral gyral and intracranial corticospinal tract tissue damage estimates (regression coefficient - 0.24, [95% CI - 0.62, 0.14], p = 0.222), but step-changes were evident between intracranial corticospinal tract and C1 (1.14, [95% CI 0.74, 1.53], p < 0.001), and between C5 and C6 cord levels (0.98, [95% CI 0.58, 1.38], p < 0.001).

DISCUSSION

Analysis of brain and cervical spinal MRI data in a common domain enabled investigation of pathophysiological hypotheses in vivo. A cranio-caudal step-change in MND patients was observed, and requires further investigation in larger cohorts.

Effect of remote ischemic conditioning on heart rate responses to walking in people with multiple sclerosis

Background

Remote ischemic conditioning (RIC), exposure of body parts to brief periods of circulatory occlusion and reperfusion, has been shown to improve cardiovascular responses to exercise in healthy individuals but its effects in people with MS are unknown.

Objective

This study aimed to assess the effect of RIC on heart rate responses to walking in people with MS.

Design

Double blind randomized controlled trial.

Setting

Multiple sclerosis clinic of tertiary care center teaching hospital in the United Kingdom.

Methods

Three cycles of RIC were delivered by occluding the upper arm with a blood pressure cuff inflated to a pressure of 30 mmHg above the systolic blood pressure. In the sham group, the blood pressure cuff was inflated to 30 mmHg below diastolic blood pressure. Heart rate responses to the 6-minute walk test (6MWT), the tolerability of RIC using a numerical rating scale for discomfort (0-10), and adverse events were studied.

Results

Seventy-five participants (RIC -38 and Sham-37) completed the study. RIC was well tolerated. Compared to sham, RIC significantly decreased the rise in heart rate (P = 0.04) and percentage of predicted maximum heart rate (P = 0.016) after the 6MWT.

Conclusion

RIC was well tolerated and improved the heart rate response to walking in people with MS. Further studies on RIC in the management of MS are needed.

How Diverse Is Medicinal Chemistry? Insights into Race, Ethnicity, Origin, Gender, and Geography

A bibliometric study of authors across medicinal chemistry journals over 20 years reveals important trends. Most United States (US) based authors are assigned as racially/ethnically Asian or White; few are Black or Hispanic. More US coauthors have the same race/ethnicity as the corresponding author than expected. The percentage of female authors increased globally, but only slowly. Since 2010, the number of female and male authors declined by 9% and 30%, respectively. Geographically, most authors are male except in Italy where there is gender balance. Gender homophily is observed globally. Geographically, the discipline is now more widely practiced. Article output doubled from 2000 to 2010 with a large increase in articles from China. China excepted, output has since declined. The average number of authors per article rose by a third since 2000. The value of high diversity groups in education, research, and industry cannot be overstated. We recommend diversity is addressed by every medicinal chemist.

Magnetic resonance spectroscopy reveals mitochondrial dysfunction in amyotrophic lateral sclerosis

Mitochondrial dysfunction is postulated to be central to amyotrophic lateral sclerosis (ALS) pathophysiology. Evidence comes primarily from disease models and conclusive data to support bioenergetic dysfunction in vivo in patients is currently lacking. This study is the first to assess mitochondrial dysfunction in brain and muscle in individuals living with ALS using 31P-magnetic resonance spectroscopy (MRS), the modality of choice to assess energy metabolism in vivo. We recruited 20 patients and 10 healthy age and gender-matched control subjects in this cross-sectional clinico-radiological study. 31P-MRS was acquired from cerebral motor regions and from tibialis anterior during rest and exercise. Bioenergetic parameter estimates were derived including: ATP, phosphocreatine, inorganic phosphate, adenosine diphosphate, Gibbs free energy of ATP hydrolysis (ΔGATP), phosphomonoesters, phosphodiesters, pH, free magnesium concentration, and muscle dynamic recovery constants. Linear regression was used to test for associations between brain data and clinical parameters (revised amyotrophic functional rating scale, slow vital capacity, and upper motor neuron score) and between muscle data and clinico-neurophysiological measures (motor unit number and size indices, force of contraction, and speed of walking). Evidence for primary dysfunction of mitochondrial oxidative phosphorylation was detected in the brainstem where ΔGATP and phosphocreatine were reduced. Alterations were also detected in skeletal muscle in patients where resting inorganic phosphate, pH, and phosphomonoesters were increased, whereas resting ΔGATP, magnesium, and dynamic phosphocreatine to inorganic phosphate recovery were decreased. Phosphocreatine in brainstem correlated with respiratory dysfunction and disability; in muscle, energy metabolites correlated with motor unit number index, muscle power, and speed of walking. This study provides in vivo evidence for bioenergetic dysfunction in ALS in brain and skeletal muscle, which appears clinically and electrophysiologically relevant. 31P-MRS represents a promising technique to assess the pathophysiology of mitochondrial function in vivo in ALS and a potential tool for future clinical trials targeting bioenergetic dysfunction.

Upper limb entrapment neuropathies in multiple sclerosis

Introduction

Entrapment neuropathies of upper limbs such as carpal tunnel and cubital tunnel syndromes are common in the general population. Identification of entrapment neuropathies of upper limbs in patients with multiple sclerosis can be clinically challenging as signs and symptoms could be attributed to multiple sclerosis. People at later stages of multiple sclerosis use mobility aids and wheelchairs. Weakness of hands in this cohort due to entrapment neuropathies could adversely affect their mobility and independence.

Methods

This was a retrospective review of records of patients with multiple sclerosis referred for clinical neurophysiological studies with clinical suspicion of upper limb entrapment neuropathies over a 10-year period. We collected demographic details, clinical features, clinical neurophysiological data and details of aids and appliances used for mobility.

Results

Among 71 patients, 38 (53.5%) patients had at least one entrapment neuropathy of upper limb confirmed by clinical neurophysiological studies. Twelve (31%) patients had median nerve entrapment, 20 (53%) had ulnar nerve entrapment and six (16%) had both. Risk of ulnar nerve entrapment was significantly higher in patients using a powered wheelchair (odds ratio 5.7, 95% confidence interval (1.7-18.7, p = 0.0037).

Discussion

Entrapment neuropathies should be considered in patients with multiple sclerosis reporting sensory and motor symptoms of hands.

Caregiver Delivered Sensory Electrical Stimulation for Post Stroke Upper Limb Spasticity: A Single Blind Crossover Randomized Feasibility Study

We developed a 64 channel sensory electrical stimulator which delivers a dynamic and variable ‘Sensory Barrage’ Stimulation (SBS). Our aim was to assess the feasibility of caregivers delivering the stimulation in the community for a clinical trial comparing single channel Transcutaneous Electrical Nerve Stimulation (TENS) with SBS for post stroke upper limb spasticity. We trained caregivers of 16 participants with post stroke upper limb spasticity to sequentially administer SBS and TENS for 60 min daily for four weeks each, with a washout period of two weeks in between. Outcome measures tested were recruitment and retention rates, compliance with interventions and daily recording of Participant -reported Numerical Rating Scale (NRS). We also collected results of Action Research Arm Test (ARAT), Leeds Arm Spasticity Impact Scale (LASIS) and Modified Ashworth Scale (MAS) for spasticity. Out of 21 potential participants, 16 consented and 15 completed the protocol. Ten participants received TENS for 80% (23/28) of the intended hours. Eleven participants completed NRS for at 80% (45/56) of the study days. All participants attended all visits. The MAS reduced by at least one in five participants after SBS and in three after TENS. Minimal Clinically Important Difference (MCID) of four points increase in ARAT was seen in five participants following TENS, and in four following SBS. A MCID of 18% decrease in NRS was reported by eight participants after TENS and three after SBS. This study demonstrated the feasibility of undertaking a trial of sensory electrical stimulation for post-stroke spasticity with caregivers delivering intervention in community. The study was not powered to detect efficacy of the interventions. Trial registration number: NCT02907775.Date 20-9-2016.

Identification of Cardiac Magnetic Resonance Imaging Thresholds for Risk Stratification in Pulmonary Arterial Hypertension

Rationale: Pulmonary arterial hypertension (PAH) is a life-shortening condition. The European Society of Cardiology and European Respiratory Society and the REVEAL (North American Registry to Evaluate Early and Long-Term PAH Disease Management) risk score calculator (REVEAL 2.0) identify thresholds to predict 1-year mortality.

Objectives: This study evaluates whether cardiac magnetic resonance imaging (MRI) thresholds can be identified and used to aid risk stratification and facilitate decision-making.

Methods: Consecutive patients with PAH (n = 438) undergoing cardiac MRI were identified from the ASPIRE (Assessing the Spectrum of Pulmonary Hypertension Identified at a Referral Center) MRI database. Thresholds were identified from a discovery cohort and evaluated in a test cohort.

Measurements and Main Results: A percentage-predicted right ventricular end-systolic volume index threshold of 227% or a left ventricular end-diastolic volume index of 58 ml/m² identified patients at low (<5%) and high (>10%) risk of 1-year mortality. These metrics respectively identified 63% and 34% of patients as low risk. Right ventricular ejection fraction >54%, 37–54%, and <37% identified 21%, 43%, and 36% of patients at low, intermediate, and high risk, respectively, of 1-year mortality. At follow-up cardiac MRI, patients who improved to or were maintained in a low-risk group had a 1-year mortality <5%. Percentage-predicted right ventricular end-systolic volume index independently predicted outcome and, when used in conjunction with the REVEAL 2.0 risk score calculator or a modified French Pulmonary Hypertension Registry approach, improved risk stratification for 1-year mortality.

Conclusions: Cardiac MRI can be used to risk stratify patients with PAH using a threshold approach. Percentage-predicted right ventricular end-systolic volume index can identify a high percentage of patients at low-risk of 1-year mortality and, when used in conjunction with current risk stratification approaches, can improve risk stratification. This study supports further evaluation of cardiac MRI in risk stratification in PAH.

Effect of remote ischaemic preconditioning on walking in people with multiple sclerosis: double-blind randomised controlled trial

Background

Remote ischaemic preconditioning (RIPC) is the exposure of body parts to brief periods of circulatory occlusion and reperfusion. Recent studies have also shown that RIPC can improve exercise performance in healthy individuals.

Objective

This study aimed to assess the effect of RIPC on walking in people with multiple sclerosis (MS).

Methods

This was a double-blind randomised controlled clinical trial. We used three cycles of RIPC delivered by occluding the upper arm with a blood pressure (BP) cuff inflated to a pressure of 30 mm Hg above the systolic BP. In patients in the sham intervention group, the BP cuff was inflated only to 30 mm Hg below diastolic BP. Outcome measures included the Six-Minute Walk Test (6MWT), gait speed, the Borg rate of perceived exertion (RPE) scale, the tolerability of the RIPC using a Numerical Rating Scale for discomfort from 0 to 10, and adverse events. We identified responders meeting the minimal clinically important difference (MCID) established in the literature in each group.

Results

Seventy-five participants completed the study (RIPC: 38 and Sham: 37). The distance walked during the 6MWT improved by 1.9% in the sham group and 5.7% in the RIPC group (p=0.012). The number of responders meeting MCID criteria in the RIPC group was significantly greater compared with the sham intervention group. No serious adverse events occurred.

Conclusion

Single cycle of RIPC resulted in immediate improvement in walking distances during 6MWT in people with MS.

Trial registration numbers

NCT03153553

Longitudinal multi-modal muscle-based biomarker assessment in motor neuron disease

Background

Clinical phenotypic heterogeneity represents a major barrier to trials in motor neuron disease (MND) and objective surrogate outcome measures are required, especially for slowly progressive patients. We assessed responsiveness of clinical, electrophysiological and radiological muscle-based assessments to detect MND-related progression.

Materials and methods

A prospective, longitudinal cohort study of 29 MND patients and 22 healthy controls was performed. Clinical measures, electrophysiological motor unit number index/size (MUNIX/MUSIX) and relative T2- and diffusion-weighted whole-body muscle magnetic resonance (MR) were assessed three times over 12 months. Multi-variable regression models assessed between-group differences, clinico-electrophysiological associations, and longitudinal changes. Standardized response means (SRMs) assessed sensitivity to change over 12 months.

Results

MND patients exhibited 18% higher whole-body mean muscle relative T2-signal than controls (95% CI 7–29%, p < 0.01), maximal in leg muscles (left tibialis anterior 71% (95% CI 33–122%, p < 0.01). Clinical and electrophysiological associations were evident. By 12 months, 16 patients had died or could not continue. In the remainder, relative T2-signal increased over 12 months by 14–29% in right tibialis anterior, right quadriceps, bilateral hamstrings and gastrocnemius/soleus (p < 0.01), independent of onset-site, and paralleled progressive weakness and electrophysiological loss of motor units. Highest clinical, electrophysiological and radiological SRMs were found for revised ALS-functional rating scale scores (1.22), tibialis anterior MUNIX (1.59), and relative T2-weighted leg muscle MR (right hamstrings: 0.98), respectively. Diffusion MR detected minimal changes.

Conclusion

MUNIX and relative T2-weighted MR represent objective surrogate markers of progressive denervation in MND. Radiological changes were maximal in leg muscles, irrespective of clinical onset-site.

Electronic supplementary material

The online version of this article (10.1007/s00415-019-09580-x) contains supplementary material, which is available to authorized users.

Study of Two Dose Regimens of Ticagrelor Compared With Clopidogrel in Patients Undergoing Percutaneous Coronary Intervention for Stable Coronary Artery Disease

BACKGROUND

Ticagrelor has superior efficacy to clopidogrel in the management of acute coronary syndromes but has not been assessed in patients undergoing percutaneous coronary intervention for stable coronary artery disease. We compared the pharmacodynamic effects of ticagrelor and clopidogrel in this stable population.

METHODS

One hundred eighty aspirin-treated stable coronary artery disease patients, who were planned to undergo elective percutaneous coronary intervention in a single center, were randomized 1:1:1 to either a standard clopidogrel regimen or 1 of 2 regimens of ticagrelor, either 90 mg (T90) or 60 mg twice daily (T60), both with a 180 mg loading dose. Cellular adenosine uptake was assessed, at the time of the procedure and pre- and postdose at 1 month, by adding adenosine 1 µmol/L to aliquots of anticoagulated whole blood and mixing with a stop solution at 0, 15, 30, and 60 seconds, then measuring residual plasma adenosine concentration by high-performance liquid chromatography. Systemic plasma adenosine concentration and platelet reactivity were assessed at the same timepoints. High-sensitivity troponin T was measured pre- and 18 to 24 hours postpercutaneous coronary intervention.

RESULTS

One hundred seventy-four patients underwent an invasive procedure, of whom 162 received percutaneous coronary intervention (mean age 65 years, 18% female, 21% with diabetes mellitus). No effect on in vitro adenosine uptake was seen postdose at 1 month for either ticagrelor dose compared with clopidogrel (residual adenosine at 15 seconds, mean±SD: clopidogrel 0.274±0.101 µmol/L; T90 0.278±0.134 µmol/L; T60 0.288±0.149 µmol/L; P=0.37). Similarly, no effect of ticagrelor on in vitro adenosine uptake was seen at other timepoints, nor was plasma adenosine concentration affected (all P>0.1). Both maintenance doses of ticagrelor achieved more potent and consistent platelet inhibition than clopidogrel (VerifyNow P2Y12 reaction units, 1 month, mean±SD: predose, T60: 62±47, T90: 40±38, clopidogrel 181±44; postdose, T60: 34±30, T90: 24±21, clopidogrel 159±57; all P<0.0001 for ticagrelor versus clopidogrel). High platelet reactivity was markedly less with both T60 and T90 compared with clopidogrel (VerifyNow P2Y12 reaction units>208, 1 month postdose: 0%, 0%, and 21%, respectively). Median (interquartile range) high-sensitivity troponin T increased 16.9 (6.5-46.9) ng/L for clopidogrel, 22.4 (5.5-53.8) ng/L for T60, and 17.7 (8.1-43.5) ng/L for T90 (P=0.95). There was a trend toward less dyspnea with T60 versus T90 (7.1% versus 19.0%; P=0.09).

CONCLUSIONS

Maintenance therapy with T60 or T90 had no detectable effect on cellular adenosine uptake at 1 month, nor was there any effect on systemic plasma adenosine levels. Both regimens of ticagrelor achieved greater and more consistent platelet inhibition than clopidogrel but did not appear to affect troponin release after percutaneous coronary intervention.

CLINICAL TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT02327624.

Reliability and acceptability of the Multiple Sclerosis Quality of Life-29 questionnaire in an English-speaking cohort

BACKGROUND

Multiple Sclerosis Quality-of-Life Questionnaire-54 (MSQoL-54) is a disease-specific instrument for assessing health-related quality of life (HRQoL). Due to the number of items, the time taken to complete it is long. A shorter 29-item version, Multiple Sclerosis Quality-of-Life Questionnaire-29 (MSQoL-29) is yet to be evaluated in English.

OBJECTIVE

To assess reliability and acceptability of English version of MSQoL-29.

METHODS

Among 100 participants with MS who first completed both MSQoL-54 and MSQoL-29, 91 completed MSQoL-29 after 4-8 weeks. We looked for internal consistency (Cronbach's alpha), acceptability, reliability (intraclass correlation coefficients (ICCs)) and agreement (Bland-Altman plots).

RESULTS

ICCs were strongly positive between MSQoL-54 and MSQoL-29 (Physical Health Composite (PHC) -ICC = 0.914, confidence interval (CI) = 0.872-0.942; Mental Health Composite (MHC) - ICC = 0.875, CI = 0.814-0.916) and between the two MSQoL-29 (PHC - ICC = 0.970, CI = 0.955-0.980; MHC - ICC = 0.937, CI = 0.904-0.958). On Bland-Altman plots, the MSQoL-29 scores of 95% of participants during two visits were within the limits of agreement (LOAs). Time taken to complete MSQoL-29 was 7.2 ± 2.9 minutes and MSQoL-54 was 19.79 ± 5.4 minutes (p = 0.0001).

CONCLUSION

MSQoL-29 has good test-retest reliability in English-speaking population and was quicker to complete.

Imaging muscle as a potential biomarker of denervation in motor neuron disease

OBJECTIVE

To assess clinical, electrophysiological and whole-body muscle MRI measurements of progression in patients with motor neuron disease (MND), as tools for future clinical trials, and to probe pathophysiological mechanisms in vivo.

METHODS

A prospective, longitudinal, observational, clinicoelectrophysiological and radiological cohort study was performed. Twenty-nine patients with MND and 22 age-matched and gender-matched healthy controls were assessed with clinical measures, electrophysiological motor unit number index (MUNIX) and T2-weighted whole-body muscle MRI, at first clinical presentation and 4 months later. Between-group differences and associations were assessed using age-adjusted and gender-adjusted multivariable regression models. Within-subject longitudinal changes were assessed using paired t-tests. Patterns of disease spread were modelled using mixed-effects multivariable regression, assessing associations between muscle relative T2 signal and anatomical adjacency to site of clinical onset.

RESULTS

Patients with MND had 30% higher relative T2 muscle signal than controls at baseline (all regions mean, 95% CI 15% to 45%, p<0.001). Higher T2 signal was associated with greater overall disability (coefficient -0.009, 95% CI -0.017 to -0.001, p=0.023) and with clinical weakness and lower MUNIX in multiple individual muscles. Relative T2 signal in bilateral tibialis anterior increased over 4 months in patients with MND (right: 10.2%, 95% CI 2.0% to 18.4%, p=0.017; left: 14.1%, 95% CI 3.4% to 24.9%, p=0.013). Anatomically, contiguous disease spread on MRI was not apparent in this model.

CONCLUSIONS

Whole-body muscle MRI offers a new approach to objective assessment of denervation over short timescales in MND and enables investigation of patterns of disease spread in vivo. Muscles inaccessible to conventional clinical and electrophysiological assessment may be investigated using this methodology.

Factors associated with HIV seroconversion in gay men in England at the start of the 21st century

OBJECTIVES

To detect and quantify current risk factors for HIV seroconversion among gay men seeking repeat tests at sexual health clinics.

DESIGN

Unmatched case control study conducted in London, Brighton and Manchester, UK.

METHODS

75 cases (recent HIV positive test following a negative test within the past 2 years) and 157 controls (recent HIV negative test following a previous negative test within the past 2 years) completed a computer-assisted self interview focused on sexual behaviour and lifestyle between HIV tests.

RESULTS

Cases and controls were similar in socio-demographics, years since commencing sex with men, lifetime number of HIV tests, reasons for seeking their previous HIV tests and the interval between last HIV tests (mean = 10.5 months). Risk factors between tests included unprotected receptive anal intercourse (URAI) with partners not believed to be HIV negative (adjusted odds ratio (AOR) and 95% confidence interval 4.1, 1.8 to 9.3), where increased risk was associated with concomitant use of nitrite inhalants, receiving ejaculate and increasing numbers of partners. Independent risk was also detected for unprotected insertive anal intercourse (UIAI) with more than one man (AOR 2.7, 1.3 to 5.5) and use of nitrite inhalants (AOR 2.4, 1.1 to 5.2).

CONCLUSIONS

HIV serodiscordant unprotected anal intercourse remains the primary context for HIV transmission among gay men, with increased risk associated with being the receptive partner, receiving ejaculate and use of nitrite inhalants. Although the HIV transmission risk of URAI is widely acknowledged, this study highlights the risk of UIAI and that nitrite inhalants may be an important facilitator of transmission when HIV exposure occurs.

Incidence and reinfection rates of genital chlamydial infection among women aged 16-24 years attending general practice, family planning and genitourinary medicine clinics in England: a prospective cohort study by the Chlamydia Recall Study Advisory Group

BACKGROUND

In England, screening for genital chlamydial infection has begun; however, screening frequency for women is not yet determined.

AIM

To measure chlamydia incidence and reinfection rates among young women to suggest screening intervals.

METHODS

An 18-month prospective cohort study of women aged 16-24 years recruited from general practices, family planning clinics and genitourinary medicine (GUM) clinics: baseline-negative women followed for incidence and baseline-positive women for reinfection; urine tested every 6 months via nucleic acid amplification; and behavioural data collected. Extra test and questionnaire completed 3 months after initial positive test. Factors associated with infection and reinfection investigated using Cox regression stratified by healthcare setting of recruitment.

RESULTS

Chlamydia incidence was mean (95% CI) 4.9 (2.7 to 8.8) per 100 person-years (py) among women recruited from general practices, 6.4 (4.2 to 9.8) from family planning clinics and 10.6 (7.4 to 15.2) from GUM clinics. Incidence was associated with young age, history of chlamydial infection and acquisition of new sexual partners. If recently acquiring new partners, condom use at last sexual intercourse was independently associated with lower incidence. Chlamydia reinfection was mean (95% CI) 29.9 (19.7 to 45.4) per 100/person-year from general practices, 22.3 (15.6 to 31.8) from family planning clinics and 21.1 (14.3 to 30.9) from GUM clinics. Factors independently associated with higher reinfection rates were acquisition of new partners and failure to treat all partners.

CONCLUSIONS

Sexual behaviours determined incidence and reinfection, regardless of healthcare setting. Our results suggest annual screening of women aged 16-24 years who are chlamydia negative, or sooner if partner change occurs. Rescreening chlamydia-positive women within 6 months of baseline infection may be sensible, especially if partner change occurs or all partners are not treated.

Modelling the effectiveness of chlamydia screening in England

BACKGROUND

Several developed countries have initiated chlamydia screening programmes. Screening for a sexually transmitted infection has both direct individual and indirect population-wide effects. Mathematical models can incorporate these non-linear effects and estimate the likely impact of different screening programmes and identify areas where more data are needed.

METHODS

A stochastic, individual based dynamic network model, parameterised from UK screening studies and data on sexual behaviour and chlamydia epidemiology, was used to investigate the likely impact of opportunistic screening on chlamydia prevalence. Three main strategies were considered for <25 year olds: (1) annual offer to women; (2) annual offer to women or if changed partner within last 6 months; (3) annual offer to men and women. Sensitivity analyses were performed for key screening parameters including uptake rate, targeted age range, percentage of partners notified, and screening interval.

RESULTS

Under strategy 1, continuous opportunistic screening of women <25 years of age is expected to reduce the population prevalence by over 50% after 5 years. Prevalence is also expected to decrease in unscreened older women and in men. For all three strategies screening those aged over 25 results in small additional reductions in prevalence. Including men led to a faster and greater reduction in overall prevalence, but involved approximately twice as many tests as strategy 1 and 10% more than strategy 2. The frequency of attendance at healthcare sites limits the number of opportunities to screen and the effect of changing the screening interval.

CONCLUSIONS

The model suggests that continuous opportunistic screening at high uptake rates could significantly reduced chlamydia prevalence within a few years. Opportunistic programmes depend on regular attendance at healthcare providers, but there is a lack of high quality data on patterns of attendance. Inequalities in coverage may result in a less efficient and less equitable outcome.

Evolution of short sequence repeats in Mycobacterium tuberculosis

Whole genome comparison has revealed the presence of short sequence repeats (also called mycobacterial interspersed repeat units and variable number tandem repeat units) used for genotyping schemes. In this study, we have used deletion analysis, single nucleotide polymorphism data and spoligotype taken from published data from others to investigate the evolution of selected repeats that form the common denominators of the majority of established schemes. Analysis of the number of repeats per locus from over 400 isolates revealed that the general trend globally appears to be loss of repeats in modern strains compared with ancestral strains.

No time to wait: how many HIV-infected homosexual men are diagnosed late and consequently die? (England and Wales, 1993-2002)

OBJECTIVES

To present national trends of the estimated number and proportion of late HIV diagnoses and short-term mortality following diagnosis among men who have had sex with men (MSM). To determine separately risk factors for late diagnosis and short-term mortality.

METHODS

Analysis of national HIV/AIDS case reports of new diagnoses linked to CD4 cell counts from the CD4 Surveillance Scheme. Inverse probability weighting adjusted for individuals with no CD4 cell count at diagnosis. Outcomes were late diagnosis (CD4 cell count <200 x 10(6) cells/l at diagnosis) and short-term mortality (death within 1 year of diagnosis).

RESULTS

Of 14,158 new diagnoses, 31% were estimated as late diagnoses. Despite a decreasing trend (P trend <0.01) an estimated 430 (25%) MSM were still diagnosed late in 2001. Late diagnosis disproportionately affected individuals diagnosed outside London, of non-white ethnicity, and of older age. There were 710 (5.0% of 14 158) deaths within a year of HIV diagnosis. Estimated short-term mortality was 14% for MSM diagnosed late and 1% for other MSM (adjusted odds ratio, 10.8; 95% confidence interval, 7.7-15.9). Short-term mortality declined concurrently with availability of highly active antiretroviral therapy and was independently associated with age and diagnosis outside London but not ethnicity.

CONCLUSIONS

The continued late diagnosis of one in four MSM means these individuals lose the option to start therapy early, miss opportunities to prevent further transmission and are approximately 10 times more likely to die within a year of diagnosis. Early diagnosis of all MSM in 2001 could have reduced short-term mortality by 84% and all mortality in that year by 22%.

Recent trends in diagnoses of HIV and other sexually transmitted infections in England and Wales among men who have sex with men

OBJECTIVES

To examine trends in rates of diagnoses of HIV and other sexually transmitted infections (STIs) in men who have sex with men (MSM) in England and Wales between 1997 and 2002.

METHODS

Estimates of the MSM population living in England and Wales, London and the rest of England and Wales were applied to surveillance data, providing rates of diagnoses of HIV and STIs and age group specific rates for HIV and uncomplicated gonorrhoea.

RESULTS

Between 1997 and 2002, rates of diagnoses of HIV and acute STIs in MSM increased substantially. Rates in London were higher than elsewhere. Rises in acute STIs were similar throughout England and Wales, except for uncomplicated gonorrhoea and infectious syphilis, with greater increases outside London. Rates of gonorrhoea diagnoses doubled between 1999 and 2001 (661/100,000, 1271/100,000, p<0.001) in England and Wales followed by a slight decline to 1210/100,000 (p=0.03) in 2002-primarily the result of a decline in diagnoses among men aged 25-34 (1340/100,000, 1128/100,000, p<0.001) and 35-44 (924/100,000, 863/100,000, p=0.03) in London. HIV was the third most common STI diagnosed in MSM in England and Wales and the second in London, with the highest rate (1286/100,000) found among men aged 35-44 in London in 2002.

CONCLUSIONS

Rates of diagnosis of HIV and other STIs have increased substantially among MSM in England and Wales. Increases show heterogeneity by infection, geography, and age over time. Rates in London were twice those seen elsewhere, with greatest changes over time. The observed changes reflect concomitant increases in high risk behaviour documented in behavioural surveillance survey programmes.

Prevalent diagnosed HIV in England, Wales and Northern Ireland: adjusted totals 1996 to 2001 and extrapolations to 2004

OBJECTIVE

To predict trends in diagnosed HIV prevalence by extrapolation to 2004 using data from the annual surveys of individuals receiving HIV-related care in England, Wales and Northern Ireland from 1996 to 2001.

METHODS

Data from the annual surveys of prevalent HIV infections diagnosed (SOPHID) were adjusted for under-reporting and non-attendance and separately extrapolated for infections acquired homosexually, heterosexually and by other routes. The data were extrapolated using negative binomial and linear regression models based on the 1996 to 2001 annual surveys.

RESULTS

The negative binomial model predicted an increase of 56% in diagnosed HIV prevalence in England, Wales and Northern Ireland between 2001 and 2004. The linear model predicted an increase of 25% for the same time period. The predicted increases are mostly driven by the large rise in the number of new diagnoses, in particular in individuals infected heterosexually.

CONCLUSION

Increases in HIV prevalence in England, Wales and Northern Ireland have diverged from a linear trend. Negative binomial modelling of the data predicts that large rises in prevalence will continue during the early 2000s.