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Biomedical subjects

K Tilling

Publications and source records attributed to K Tilling.

At least 19 recordsLinked to original sources
PubMed2006

Establishing normal reference ranges for PSA change with age in a population-based study: The Krimpen study.

BACKGROUND: We aim to establish the normal pattern of prostate specific antigen (PSA) change with age to provide a baseline from which disease progression might be identified in prostate cancer patients included in active surveillance programs. METHODS: In a community-based study, PSA values were determined at baseline and after 2.1 and 4.2 years in men without prostate cancer. A bivariate multilevel growth curve model was used to estimate the pattern of change of PSA with age. RESULTS: The final model showed that PSA was related to age only. The future PSA of an individual can be predicted based on his age and known history of PSA. The model was also used to calculate PSA doubling time for men with different PSA values at different ages. CONCLUSIONS: This method establishes normal PSA levels by age using PSA history in men without prostate cancer. The model provides baseline data from which disease progression might be detected.

Age Factors↗
PubMed2006

Relationships between long-term stroke disability, handicap and health-related quality of life.

OBJECTIVES: To estimate levels of disability, handicap and health-related quality of life (HRQOL) up to 3 years after stroke and examine the relationships between these domains. DESIGN: A longitudinal, observational study SETTING: Population-based register of first-ever strokes METHODS: Subjects, registered between 1 January 1995 and 31 December 1997, were assessed at 1 year (n = 490) and 3 years (n = 342) post-stroke for disability [Barthel index (BI)], handicap [Frenchay activity index (FAI)] and HRQOL (SF-36). BI was categorised as severe, moderate, mild and independent (0-9, 10-14, 15-19 and 20); FAI was categorised as inactive, moderately active and very active (0-15, 16-30 and 31-45). SF-36 domains include: Physical Functioning (PF), Role Physical (RP), Bodily Pain (BP), General Health (GH), Vitality (VT), Social Functioning (SF), Role Emotional (RE) and Mental Health (MH). Physical (PHSS) and Mental Health (MHSS) Summary Scores were computed. RESULTS: at 1 and 3 years, 26.1 and 26.3%, respectively, were disabled (BI < 15); 55 and 51%, respectively, were handicapped (FAI = 0-15); and survivors had low mean PHSS (37.1 and 37.9), but satisfactory mean MHSS (46.6 and 47.7). There was a graded positive relationship between all SF-36 domains and the categories of BI and FAI. Spearman rank correlations were significant between BI and all SF-36 domains at both time points: strong (r > 0.70) with PF, moderate (r = 0.31-0.70) with RP, SF and PHSS, but weak (r < 0.30) with other domains. Correlations between FAI and SF-36 domains were strong with PF, weak with BP, RE and MHSS, and moderate with other domains. CONCLUSIONS: Disability and handicap remain highly prevalent up to 3 years after stroke. Patients' perception of physical health is persistently low, but mental health perception is satisfactory up to 3 years. Due to variable correlations between different HRQOL domains with disability and handicap, it is suggested that disability, handicap and HRQOL should all be assessed to acquire a broader measure of stroke outcome.

Disability Evaluation↗
PubMed2005

Effect of recommended positioning on stroke outcome at six months: a randomized controlled trial.

OBJECTIVE: To evaluate the effect on patient outcome of a teaching package for nurses designed to improve the positioning of stroke patients. DESIGN: Cluster randomized controlled trial with six-month follow-up. SETTING: Ten stroke rehabilitation hospital units located within one UK inner city region. These were randomized to control or intervention group. SUBJECTS: A sample of 120 patients admitted within four weeks of a first stroke and with a hemiplegia. No eligible patient refused to participate. Eighty-three (69%) completed the study. INTERVENTION: All nursing staff on the intervention units received a group teaching package to improve their clinical practice in patient positioning. MAIN OUTCOME MEASURE: Rivermead Mobility Index (RMI) at six months post stroke. Patient's position was recorded using an established observational tool. RESULTS: After the teaching there was some evidence of better positioning in the intervention than the control group (difference in percentage of correct positions per patient 4.9%, 95% confidence interval (Cl -0.1% to 9.9%, p = 0.055). There was no evidence of differences between the two groups in any of the outcome measures at six months although there was a trend towards increased elbow flexor tone in the control group. CONCLUSIONS: A teaching intervention to improve patient positioning made no significant impact on outcome at six months post stroke. However, following the teaching there was only a slightly higher incidence of recommended patient positioning within the intervention group. Thus, a teaching package may not be powerful enough to enable any effect on patient outcome to be measured.

Aged↗
PubMed2004

Older stroke patients in Europe: stroke care and determinants of outcome.

BACKGROUND: in order to implement cost-effective stroke services for older patients, it is necessary to identify how stroke care is currently provided for these patients and how provision relates to outcome. OBJECTIVES: to estimate the structure and process of care, and identify independent factors associated with 3 month mortality and functional outcome in patients aged over 75 years compared with younger stroke patients across Europe. SETTING: 13 hospitals in 10 European countries. SUBJECTS AND METHODS: 1,847 subjects with first in a lifetime stroke admitted to hospital. Sociodemographic details, acute case severity, resource use and 3-month survival and dependency were collected. RESULTS: from a total of 1,847 patients, 1,112 patients (60%) were under 75 years. Older stroke patients were more likely to be incontinent, dysphasic, dysphagic and comatose (P < 0.001). Computed tomography scan rates were higher in younger (87%) than in older patients (79%) (P < 0.001). Access to organised stroke care was higher in older (58%) than in younger patients (51%) (P = 0.002). Median acute length of stay was longer in younger (14 days, range 7-21 days) than in older patients (11 days, range 8-22 days) (P = 0.04). Nursing time in hospital was higher in older patients (P = 0.01), whilst therapy time was higher in younger patients (P = 0.03). By 3 months, younger patients were more likely to receive outpatient care (P < 0.001), physiotherapy (P < 0.001) and occupational therapy (P < 0.001). For older stroke patients, not having a computed tomography scan (OR = 0.2, 95% confidence intervals (CI) = 0.01-0.6, P = 0.003) was significantly related to mortality at 3 months after adjusting for case mix. Access to organised stroke care was significantly associated with reduced 3-month mortality in younger patients only (OR = 0.29, 95% CI = 0.14-0.6, P < 0.001). CONCLUSION: stroke care varies considerably across European centres, with older people more likely to gain access to organised stroke care in many centres but less likely to receive diagnostic investigations, therapy input and outpatient review. Where there is evidence of age discrimination for access to stroke services, guidelines need to be adopted to ensure patients of all ages receive optimal evidence-based stroke care at all stages of their illness.

Adult↗
PubMed2004

Variations in care and outcome in the first year after stroke: a Western and Central European perspective.

BACKGROUND: There are significant variations in the short term patterns of care and outcome after a first stroke in Europe. OBJECTIVE: To estimate the variation in stroke care and outcome up to 1 year after a stroke in selected European centres. METHODS: Hospital based stroke registers were established in 11 hospitals in seven western and central European countries to collect demographic, clinical, and resource use data at the time of first ever stroke during 1993-4. At 3 and 12 months, details of survival, activities of daily living score, and use of services were recorded. Univariate comparisons between centres were made using the chi2 test and stepwise regression was used to identify associations between centre, case mix, therapy provision, and outcomes. RESULTS: Of the 4048 patients registered, 23% were lost to follow up and 38% had died at 1 year. The proportions of survivors who felt they needed assistance at 12 months ranged from 35% in Italy to 77% in UK2. There were comparatively high amounts of therapy provided up to 1 year in UK3, France and Germany 1, mainly at home. At 1 year, social services were still providing support in UK1, UK5 and France, with some support in Germany 1 and family support was provided in France. In multivariate analysis, after adjustment for case mix and receipt of rehabilitation, non-UK centres had improved activities of daily living (p<0.001). Older age was indicative of more need for assistance, but less likelihood of assistance from the family. Those in France were more likely to get assistance from their family than any other centre. Mainland European patients were more likely to get help from their family than those in the UK. Patients in all areas except UK2 and UK3 were more likely to be dead or dependent at 1 year than patients in UK1. CONCLUSIONS: There were significant variations in the pathways of care for stroke across European centres in the mid 1990s, which were associated with variation in outcome, and remain unexplained. Family support is more prevalent in southern Europe and service support more prevalent in the UK.

Activities of Daily Living↗
PubMed2003

Variation in the management of acute physiological parameters after ischaemic stroke: a European perspective.

Studies have shown significant variation in stroke case fatality across Europe. These variations suggest the need to explore whether differences in physiological support in acute stroke exist across Europe. Data were collected in four European centres over 6 months. These included clinical status and management of acute physiology (hydration, oxygenation, nutrition, hypertension, hyperglycaemia and temperature in the first week of ischaemic stroke) and survival at 3 months. Differences in acute supportive care between centres were adjusted for case mix. Patients admitted to centres in London (n = 106), Dijon (n = 95), Erlangen (n = 91) and Warsaw (n = 72) were studied. There were significant differences in incontinence, dysphasia, dysphagia, conscious level, pyrexia, hyperglycaemia and comorbidity between centres. After adjusting for case mix, there were significant differences in intravenous fluid use (P = 0.04), enteral feeding (P = 0.003), initiation of new antihypertensive therapy (P = 0.0006) and insulin therapy (P = 0.004) between centres, with the London centre having the lowest uptake of interventions. Three-month case fatality rates varied from 10 to 28%. This pilot study shows significant variation in acute physiological support in acute stroke across four European centres, which remains unexplained by case mix. Further research is required to link variation in acute care with stroke outcome, to identify which interventions appear to be the most effective.

Acute Disease↗
PubMed2003

Reliability and validity of a postal version of the Reintegration to Normal Living Index, modified for use with stroke patients.

OBJECTIVE: To adapt the Reintegration to Normal Living Index (RNLI) for postal use with stroke patients. DESIGN: Reliability was examined using test-retest on 26 stroke patients. Construct validity was tested on 76 patients by examining correlations between the modified RNLI and related scales. SUBJECTS: Patients at three months to one year post stroke. RESULTS: All items demonstrated better than chance agreement between test and retest and seven items substantial agreement (kappa = >0.61). The modified RNLI correlated positively with related scales. Patients with stronger reintegration to normal living had better outcomes in anxiety, depression, daily activity and quality of life. CONCLUSION: This postal instrument appears reliable and valid and may be a useful outcome measure in stroke studies.

Activities of Daily Living↗
PubMed2001

A new method for predicting recovery after stroke.

BACKGROUND AND PURPOSE: Several prognostic factors have been identified for outcome after stroke. However, there is a need for empirically derived models that can predict outcome and assist in medical management during rehabilitation. To be useful, these models should take into account early changes in recovery and individual patient characteristics. We present such a model and demonstrate its clinical utility. METHODS: Data on functional recovery (Barthel Index) at 0, 2, 4, 6, and 12 months after stroke were collected prospectively for 299 stroke patients at 2 London hospitals. Multilevel models were used to model recovery trajectories, allowing for day-to-day and between-patient variation. The predictive performance of the model was validated with an independent cohort of 710 stroke patients. RESULTS: Urinary incontinence, sex, prestroke disability, and dysarthria affected the level of outcome after stroke; age, dysphasia, and limb deficit also affected the rate of recovery. Applying this to the validation cohort, the average difference between predicted and observed Barthel Index was -0.4, with 90% limits of agreement from -7 to 6. Predicted Barthel Index lay within 3 points of the observed Barthel Index on 49% of occasions and improved to 69% when patients' recovery histories were taken into account. CONCLUSIONS: The model predicts recovery at various stages of rehabilitation in ways that could improve clinical decision making. Predictions can be altered in light of observed recovery. This model is a potentially useful tool for comparing individual patients with average recovery trajectories. Patients at elevated risk could be identified and interventions initiated.

Activities of Daily Living↗
PubMed2001

Multilevel growth curve models with covariate effects: application to recovery after stroke.

In measuring the progression of, or recovery from, a disease an individual's outcome may be assessed on a number of occasions. A model of the relationship between outcome and time since disease occurred which accounts for patient characteristics could be used to describe patterns of recovery, to predict outcome for a patient, or to evaluate health interventions. We use multilevel models to analyse such data, focusing on the choice of powers of time both for mean outcome and covariate effects. We give equations for predicted outcome and corresponding standard errors (i) based only on baseline characteristics, and (ii) by conditioning on previous outcomes for an individual. In a study of 331 stroke patients, outcome was measured approximately 0, 2,4,6 and 12 months after stroke. Patient characteristics included age, sex, and pre-stroke handicap, together with stroke-severity indicators (presence of limb deficit, dysphasia, dysarthria or incontinence). Of these, only the effects of age, dysphasia and presence of deficit varied with time. Conditioning on previous observations improved the accuracy of predictions. The outcome variable clearly had a skewed distribution, and the model residuals showed evidence of non-Normality. We discuss alternative models for non-Normal data, and show that, here, the standard (Normal errors) multilevel model gives equivalent parameter estimates and predictions to those obtained from alternative models.

Aged↗
PubMed2001

Preliminary results of a randomized controlled trial of prophylactic shock wave lithotripsy for small asymptomatic renal calyceal stones.

OBJECTIVE: To report a prospective, randomized study to determine whether prophylactic extracorporeal shockwave lithotripsy (ESWL) is justified as a treatment for small, asymptomatic calyceal stones. PATIENTS AND METHODS: The study included 228 patients with small (< 15 mm total diameter) asymptomatic calyceal stones; 113 patients were randomized to undergo ESWL and 115 to the control group who were kept under observation. Outcome measurements included the stone-free rate, requirement for additional treatment, symptoms, quality of life and renal function. RESULTS: In all, 200 patients had at least one annual follow-up; all outcome measurements reported were those at the most recent follow-up (mean 2.2 years, range 1-5). In the ESWL group 28 patients (28%) were stone-free, compared with 16 (17%) in the observation group (odds ratio 1.95, 95% confidence interval, CI, 0.97-3.89, P = 0.06). Additional treatment in the form of analgesics, antibiotics, ESWL, stent insertion and ureteroscopy, was required in 21 (21%) patients in the observation group and 15 (15%) in the ESWL group (odds ratio 0.66, 95% CI 0.32-1.37, P = 0.27). Ten patients in the observation group required invasive procedures, vs none in the ESWL group. There was no evidence of differences in the symptoms, quality of life or renal function tests between the arms of the trial at the final follow-up. CONCLUSIONS: Prophylactic ESWL for small asymptomatic renal calyceal stones does not appear to offer any advantage to patients in terms of stone-free rate, quality of life, renal function, symptoms or hospital admissions. However, a policy of observation is associated with a greater risk of requiring more invasive procedures. A longer follow-up is required to assess the validity of these preliminary findings.

Adult↗
PubMed2001

Estimation of the incidence of stroke using a capture-recapture model including covariates.

BACKGROUND: Capture-recapture is often used to assess completeness of a register. However, the usual two-source model relies on assumptions of independence of sources and equality of capture probability which are rarely satisfied in epidemiology. An alternative is to include covariates in capture-recapture models. METHODS: We use capture-recapture models including covariates to estimate incidence of stroke in South London. We estimate ascertainment-adjusted age-standardized incidence rates, and calculate confidence intervals for incidence which allow for the uncertainty in estimation of the total number of cases. RESULTS: The crude capture-recapture model (including no covariates) underestimated the number of non-fatal strokes. Demographic and stroke severity variables were associated with the probability of capture. Including covariates led to more plausible results for fatal and non-fatal strokes, and suggested that the stroke register was 88% complete. Adjusting for under-ascertainment increased the estimated incidence from 1.31 (95% CI : 1.21-1.42) to 1.49 (95% CI : 0.38-2.60) per 1000 people. CONCLUSIONS: Incidence and age-standardized incidence can be calculated using data from an incomplete register. However, sparse strata can lead to wide confidence intervals for adjusted rates. Cost-effectiveness of routine registers might be increased by using the combination of sources and covariates which most accurately estimates the total number of cases, rather than by aiming for 100% completeness.

Aged↗
PubMed2000

Early observations of the effect of extracorporeal shockwave lithotripsy on blood pressure: a prospective randomized control clinical trial.

OBJECTIVE: To determine, in a randomized controlled clinical trial, the effect of extracorporeal shock wave lithotripsy (ESWL) on blood pressure. PATIENTS AND METHODS: The trial included 228 patients with small (< 15 mm) asymptomatic calyceal stones who were randomised to undergo ESWL (113 patients) or to an untreated (observed) control group (115 patients). Blood pressure was recorded at randomization using a standardized protocol. Patients undergoing ESWL received a mean (SD) of 5281 (3462) shocks over a mean of 1.75 sessions on one of two lithotripters. Patients were then followed annually, assessing blood pressure and changes in medication. Data were analysed on an intention-to-treat basis. RESULTS: At randomization, 43% of patients in the control group and 53% in the ESWL group were hypertensive. Of the 228 randomized, 200 patients completed at least one annual follow-up, of whom 192 (93 in the control and 99 in the ESWL group) had their blood pressure recorded. The mean follow-up was 2.2 years; 35 (37%) patients in the control and 46 (46%) in the ESWL group were hypertensive (P = 0.19). Seven (7%) patients in the control group and 11 (11%) in the ESWL group were newly diagnosed to be hypertensive (P = 0.35). CONCLUSIONS: In this randomized controlled clinical trial there was no evidence that ESWL causes changes in blood pressure.

Aged↗
PubMed2000

Serial fetal lung volume measurement using three-dimensional ultrasound.

OBJECTIVE: To establish reference intervals for fetal lung growth. DESIGN: Longitudinal observational study. SUBJECTS: Fifty-eight women with initially uncomplicated singleton pregnancies were recruited from the antenatal population of a teaching hospital. Four women were excluded from the final analysis because of complications arising in their pregnancy. METHODS: Each subject was serially scanned at monthly intervals. At each visit lung volume was measured using an ultrasound-based computerized three-dimensional imaging system. Multilevel models were used to determine conditional and unconditional reference intervals. RESULTS: Reference intervals for fetal lung growth were derived. Fetal lung volume increases in a non-linear way with gestation. CONCLUSIONS: Our computerized system has the capacity to be used in conjunction with any standard two-dimensional ultrasound scanner in order to measure volume. Lung volume measurement may be useful in predicting pulmonary hypoplasia.

Adult↗
PubMed2000

The effectiveness of community-based rehabilitation for stroke patients who remain at home: a pilot randomized trial.

OBJECTIVE: To assess the effectiveness of community-based rehabilitation for stroke patients who were not admitted to hospital in South London. DESIGN: Randomized controlled trial. SETTING: Patients' homes in South London. SUBJECTS: Stroke patients not admitted to hospital after a stroke. INTERVENTION: Rehabilitation at home by rehabilitation team for up to three months or usual care. MAIN OUTCOME MEASURES: The primary outcome measure was the Barthel score. Secondary measures included the Motricity Index, Rivermead ADL, Hospital Anxiety and Depression score and Nottingham Health Profile. RESULTS: Forty-three patients who remained at home were randomized to rehabilitation team (23) or 'usual' care (20). The mean number of physiotherapy sessions was three (range 1-14) for the rehabilitation team group and two for the usual care group. Patients (with a deficit) in the rehabilitation arm of the trial were more likely to receive occupational, physical and speech therapy than those in the control arm (p = 0.03, 0.01 and 0.008, respectively). For those patients actually receiving therapy, there was no evidence that the amount received differed between the groups. However, the number of patients in each of these comparisons was very small. The outcome for patients in the rehabilitation team arm of the trial was nonsignificantly higher (0.05 < p < 0.2) than for those in the control arm for the areas of Nottingham Health Profile, anxiety, depression, caregiver strain and the proportion of patients living at home. Based on the data observed here, a trial with approximately 150 patients in each arm would be needed to have adequate power to detect a 33% difference between intervention and control groups in these outcomes. CONCLUSION: Community therapy support for patients not admitted to hospital is feasible but to determine whether it is cost- or clinically effective would require trials of adequate size.

Aged↗
PubMed1999

Capture-recapture models including covariate effects.

Capture-recapture methods are used to estimate the incidence of a disease, using a multiple-source registry. Usually, log-linear methods are used to estimate population size, assuming that not all sources of notification are dependent. Where there are categorical covariates, a stratified analysis can be performed. The multinomial logit model has occasionally been used. In this paper, the authors compare log-linear and logit models with and without covariates, and use simulated data to compare estimates from different models. The crude estimate of population size is biased when the sources are not independent. Analyses adjusting for covariates produce less biased estimates. In the absence of covariates, or where all covariates are categorical, the log-linear model and the logit model are equivalent. The log-linear model cannot include continuous variables. To minimize potential bias in estimating incidence, covariates should be included in the design and analysis of multiple-source disease registries.

Analysis of Variance↗
PubMed1999

The effect of polymethylmethacrylate, silicone, and polyacrylic intraocular lenses on posterior capsular opacification 3 years after cataract surgery.

OBJECTIVE: To compare the visual outcome, neodymium:YAG (Nd:YAG) capsulotomy rates, and percentage of posterior capsular opacification (PCO) seen with polymethylmethacrylate (PMMA), silicone, and polyacrylic intraocular lens implants 3 years after surgery. DESIGN: Randomized, prospective trial. PARTICIPANTS: Ninety eyes of 81 patients were examined at a British teaching hospital. INTERVENTION: Ninety eyes were prospectively randomized to receive a PMMA, silicone, or polyacrylic (AcrySof, Alcon, Fort Worth, TX) implant. All lenses had 6-mm disc optics with PMMA haptics. A standardized surgical protocol was performed by a single surgeon using an extracapsular technique with capsulorhexis; any surgical complications were excluded and all patients had standardized postoperative medication and follow-up. MAIN OUTCOME MEASURES: Patients were seen at 6 months and 1, 2, and 3 years after surgery. At 3 years, logarithm of the minimum angle of resolution (LogMAR) visual acuity and Pelli-Robson contrast sensitivity were measured and YAG capsulotomy rates determined. Posterior capsular opacification was assessed objectively by digital retroillumination imaging using dedicated software and calculated as the percentage area of opacified capsule. RESULTS: At 3 years, the overall follow-up rate was 71%: 19 patients were available for examination with polyacrylic lens implants, 22 with silicone, and 23 with PMMA. There was a significant difference in percentage PCO at 3 years among the lens types (P = 0.0001). Polyacrylic lenses were associated with less PCO (10%) than silicone (40%) and PMMA lenses (56%). The YAG capsulotomy rate was 0% for polyacrylic, 14% for silicone, and 26% for PMMA (P = 0.05). The visual acuity and contrast sensitivity were not significantly different among the three groups if patients with age-related macular degeneration and those requiring YAG capsulotomies are excluded. CONCLUSIONS: Intraocular lenses made from polyacrylic are associated with a significantly reduced degree of PCO and lower YAG rates.

Acrylates↗
PubMed1999

Plasma amino acids in childhood epileptic encephalopathies.

Abnormalities in plasma amino acid levels have been noted in patients with various epilepsies, and sometimes also in their first degree relatives. We sought to study plasma amino acid levels in children with epileptic encephalopathies and their parents, relating findings to the pattern of cortical glucose metabolism as determined by 18fluorodeoxyglucose (FDG) positron emission tomography (PET). Twenty-eight children with cryptogenic epileptic encephalopathies were studied prospectively. Cortical glucose metabolism was evaluated by FDG PET with combined visual and semiquantitative analysis used to detect focal cortical defects. The plasma concentration of 21 amino acids in the children and their parents was measured by ion exchange chromatography and compared with control values using non-parametric statistical methods. Multivariate analysis was used to assess antiepileptic drug effects. Children were classified as: Lennox-Gastaut syndrome following infantile spasms (six patients); de-novo Lennox-Gastaut syndrome (eight); severe myoclonic epilepsy in infancy (eight) and myoclonic-astatic epilepsy (two). Four patients remained unclassified. Fourteen patients had focal/multifocal abnormalities on PET scans. The plasma level of aspartate was significantly lower in both the children with epileptic encephalopathies and in their parents (P < 0.005). The lowered aspartate levels could not be accounted for by the antiepileptic drug medication taken by the children. Further analysis showed the lowered aspartate levels to be confined to children and their parents who lacked focal PET abnormalities. These findings suggest a possible genetic abnormality in the aspartate neurotransmitter systems in the pathogenesis of seizures in the childhood epileptic encephalopathies.

Amino Acids↗