Effectiveness and cost-effectiveness of proactive and multidisciplinary integrated care for older people with complex problems in general practice: an individual participant data meta-analysis

Purpose

to support older people with several healthcare needs in sustaining adequate functioning and independence, more proactive approaches are needed. This purpose of this study is to summarise the (cost-) effectiveness of proactive, multidisciplinary, integrated care programmes for older people in Dutch primary care.

Methods design

individual patient data (IPD) meta-analysis of eight clinically controlled trials.

Setting

primary care sector.

Interventions

combination of (i) identification of older people with complex problems by means of screening, followed by (ii) a multidisciplinary integrated care programme for those identified.

Main outcome

activities of daily living, i.e. a change on modified Katz-15 scale between baseline and 1-year follow-up.

Secondary outcomes

quality of life (visual analogue scale 0–10), psychological (mental well-being scale Short Form Health Survey (SF)-36) and social well-being (single item, SF-36), quality-adjusted life years (Euroqol-5dimensions-3level (EQ-5D-3L)), healthcare utilisation and cost-effectiveness.

Analysis

intention-to-treat analysis, two-stage IPD and subgroup analysis based on patient and intervention characteristics.

Results

included were 8,678 participants: median age of 80.5 (interquartile range 75.3; 85.7) years; 5,496 (63.3%) women. On the modified Katz-15 scale, the pooled difference in change between the intervention and control group was −0.01 (95% confidence interval −0.10 to 0.08). No significant differences were found in the other patient outcomes or subgroup analyses. Compared to usual care, the probability of the intervention group to be cost-effective was less than 5%.

Conclusion

compared to usual care at 1-year follow-up, strategies for identification of frail older people in primary care combined with a proactive integrated care intervention are probably not (cost-) effective.

Safety of Anti-TNF Treatment in Liver Transplant Recipients: A Systematic Review and Meta-analysis

BACKGROUND AND AIM

Little is known about the risk of serious infection when combining anti-tumour necrosis factor [TNF] therapy for refractory inflammatory bowel disease [IBD] with immunosuppression after liver transplantation [LT]. Our aim was to investigate the infection risk in this patient group by systematic review and meta-analysis of the available data.

METHODS

A search was conducted for full papers and conference proceedings through September 2015, regarding liver transplant recipients and anti-TNF therapy. All studies were appraised using the adapted Newcastle-Ottawa Scale [NOS]. Two reviewers independently extracted patient data [age, duration of follow-up, number of all infections, number of serious infections, time since transplant]. As an additional control population, primary sclerosing cholangitis [PSC]-IBD patients from the Leiden University Medical Center [LUMC] LT cohort were used. Poisson regression was used to compare serious infections (according to International Conference on Harmonisation [ICH] definition) per patien-year follow-up between the anti-TNF and control groups.

RESULTS

In all 465 articles and abstracts were identified, of which eight were included. These contained 53 post-LT patients on anti-TNF therapy and 23 post-LT patients not exposed to anti-TNF therapy. From the LUMC LT-cohort, 41 PSC patients with PSC-IBD not exposed to anti-TNF therapy were included as control population. The infection rate for TNF-exposed patients was 0.168 serious infections per patient year, compared with 0.149 in the control patients (rate ratio 1.12 [95% confidence interval: 0.233-5.404, P = 0.886]. When correcting for time since transplant, the infection rate was 0.194 in the TNF-exposed vs 0.115 in the non-exposed [p = 0.219].

CONCLUSIONS

No significant increase in the rate of serious infection was observed in LT recipients with PSC-IBD during exposure to anti-TNF therapy.

Meta-Regression of a Dose-Response Relationship of Methotrexate in Mono- and Combination Therapy in Disease-Modifying Antirheumatic Drug-Naive Early Rheumatoid Arthritis Patients

OBJECTIVE

To investigate a possible short-term dose-response relationship of initial treatment with methotrexate (MTX) in monotherapy and combination therapy in recent-onset rheumatoid arthritis (RA) patients.

METHODS

A systematic literature search was performed on trials and cohorts, including early, disease-modifying antirheumatic drug (DMARD)-naive RA patients treated with MTX, with data on clinical results within 6 months from treatment start. Cohen's effect sizes were calculated for the Health Assessment Questionnaire (HAQ), erythrocyte sedimentation rate (ESR)/C-reactive protein (CRP) level, and/or Disease Activity Score (DAS)/in 28 joints (DAS28) in 4 treatment groups: MTX monotherapy, or MTX in combination with synthetic (cs) DMARDs, biologic (b) DMARDs, or glucocorticoids. Random-effects meta-regression analyses were performed for each outcome, with treatment group as the predictor corrected for baseline HAQ or disease activity and assessment point.

RESULTS

Thirty-one studies including 5,589 patients were included. The meta-regression did not support higher effectiveness of increasing MTX dose in monotherapy. The number of treatment groups using combination therapy with csDMARDs was too small to perform meta-regression analyses. In combination therapy with glucocorticoids, a higher MTX dose was associated with higher (worse) outcome HAQ, but not with DAS/DAS28 or ESR/CRP level. In combination therapy with bDMARDs, a higher MTX dose was associated with higher outcome HAQ and DAS/DAS28, but not with ESR/CRP level. All effect sizes were small.

CONCLUSION

In DMARD-naive, early RA patients who start MTX, either as monotherapy or in combination with bDMARDs or glucocorticoids, a higher initial dose of MTX was not associated with better clinical outcomes. This finding suggests that there is little short-term gain from starting with high compared to low MTX doses.

Metabolic health profile in young adults with Prader-Willi syndrome: results of a 2-year randomized, placebo-controlled, crossover GH trial

CONTEXT

Patients with Prader-Willi syndrome (PWS) have an increased fat mass and decreased lean body mass. GH-treated young adults with PWS who have attained adult height benefit from continuation of growth hormone (GH) treatment, as GH maintained their improved body composition, whereas fat mass increased during the placebo period. Adults with PWS are predisposed to T2DM and cardiovascular disease. Whether GH affects metabolic health profile of this patient group is unknown.

OBJECTIVE

To investigate the effects of GH vs placebo on metabolic health, in young adults with PWS who were GH-treated for many years during childhood and had attained adult height (AH).

METHOD

A 2-year, randomized, double-blind, placebo-controlled crossover study with stratification for gender and BMI in 27 young adults with PWS. Intervention with GH (0·67 mg/m² /day) and placebo, both for 1-year duration.

RESULTS

Compared to placebo, GH treatment resulted in similar glucose and insulin levels during oral glucose tolerance test. Only fasting glucose and insulin were slightly higher during GH vs placebo (+0·2 mmol/l and +18·4 pmol/l), although both remained within normal ranges in both phases. Blood pressure and lipid profile were similar after GH vs placebo. At baseline (AH) and during GH, no patients had metabolic syndrome, while 1 developed it during placebo treatment.

CONCLUSIONS

Growth hormone treatment has no adverse effects on metabolic health profile. Thus, GH-treated young adults with PWS who have attained AH benefit from continuation of GH treatment without safety concerns regarding metabolic health.

Age affects joint space narrowing in patients with early active rheumatoid arthritis

BACKGROUND

Joint space narrowing (JSN) in rheumatoid arthritis (RA) may be a manifestation of (primary) osteoarthritis becoming more prominent with age. We investigated the severity and predictors of JSN progression among different age groups.

METHODS

10-year follow-up data of the BeSt study, a randomised controlled treat-to-target trial in early RA were used. Annual X-rays of hands and feet were scored using the Sharp/van der Heijde score (SHS). Subgroups were defined by age at baseline: ≥55, ≥40<55 and <40 years. JSN progression predictors were assessed by Poisson regression.

RESULTS

Baseline JSN scores (median (IQR)) were higher in patients ≥55 (2.0 (0.0-6.0)) compared with the other age groups: 1.0 (0.0-3.0) ≥40<55 and 0.3 (0.0-3.0) <40, p<0.001. After 10 years, total JSN and SHS were similar in all age groups. In patients ≥55 the mean erythrocyte sedimentation rate (ESR) over time (relative risk 1.02 (95% CI 1.00 to 1.03)) and the combined presence of rheumatoid factor and anticitrullinated protein antibodies (RF+/ACPA+) (3.27 (1.25-8.53)) were significantly correlated with JSN progression. In patients <40 the baseline swollen joint count (SJC; 1.09 (1.01-1.18)) and ESR over time (1.04 (1.02-1.06)) were significantly associated.

CONCLUSIONS

At baseline, patients with RA ≥55 years had more JSN than younger patients but after 10 years JSN scores were similar between age groups. Independent risk factors for JSN progression were baseline SJC and ESR over time in patients <40, RF+/ACPA+ and ESR over time in patients ≥55 years. This suggests that mechanisms leading to JSN progression are related to (residual) rheumatoid inflammation and vary between age groups. These mechanisms remain to be elucidated.

TRIAL REGISTRATION NUMBERS

NTR262, NTR265.

Tumour-free margins in vulvar squamous cell carcinoma: Does distance really matter?

BACKGROUND

There is no consensus on the width of tumour-free margins after surgery for vulvar squamous cell carcinoma (VSCC). Most current guidelines recommend tumour-free margins of ≥8 mm. The aim of this study was to investigate whether a margin of <8 mm is associated with an increased risk of local recurrence in VSCC.

METHODS

A meta-analysis of the available literature and a cohort study of 148 VSCC patients seen at a referral centre from 2000 to 2012 was performed. The primary end-point of the cohort study was a histologically confirmed ipsilateral local recurrence within 2 years after primary treatment in relation to the margin distance.

RESULTS

Based on 10 studies, the meta-analysis showed that a tumour-free margin of <8 mm is associated with a higher risk of local recurrence compared to a tumour-free margin of ≥8 mm (pooled risk ratio, 1.99 [95% confidence interval {CI}: 1.13-3.51], p = 0.02). In the cohort study, we found no clear difference in the risk of local recurrence in the <8 versus ≥8 mm group; however, 40% of the patients in the <8 mm group received additional treatment. Tumour-positive margin was the only independent risk factor for local recurrence in the multivariable analysis (hazard ratio, 0.21 [95% CI: 0.08-0.55]).

CONCLUSIONS

This work provides important data to question the commonly used 8-mm margin as a prognosticator for local recurrence. More research is needed to address the question of whether additional treatment improves the prognosis in patients with a tumour-free margin of <8 mm.

Tumour-free margins in vulvar squamous cell carcinoma: Does distance really matter?

BACKGROUND

There is no consensus on the width of tumour-free margins after surgery for vulvar squamous cell carcinoma (VSCC). Most current guidelines recommend tumour-free margins of ≥8 mm. The aim of this study was to investigate whether a margin of <8 mm is associated with an increased risk of local recurrence in VSCC.

METHODS

A meta-analysis of the available literature and a cohort study of 148 VSCC patients seen at a referral centre from 2000 to 2012 was performed. The primary end-point of the cohort study was a histologically confirmed ipsilateral local recurrence within 2 years after primary treatment in relation to the margin distance.

RESULTS

Based on 10 studies, the meta-analysis showed that a tumour-free margin of <8 mm is associated with a higher risk of local recurrence compared to a tumour-free margin of ≥8 mm (pooled risk ratio, 1.99 [95% confidence interval {CI}: 1.13-3.51], p = 0.02). In the cohort study, we found no clear difference in the risk of local recurrence in the <8 versus ≥8 mm group; however, 40% of the patients in the <8 mm group received additional treatment. Tumour-positive margin was the only independent risk factor for local recurrence in the multivariable analysis (hazard ratio, 0.21 [95% CI: 0.08-0.55]).

CONCLUSIONS

This work provides important data to question the commonly used 8-mm margin as a prognosticator for local recurrence. More research is needed to address the question of whether additional treatment improves the prognosis in patients with a tumour-free margin of <8 mm.

The influence of age and approaching death on the course of nondopaminergic symptoms in Parkinson's disease

INTRODUCTION

The influence of approaching death in addition to age and their interaction on the course of a broad spectrum of nondopaminergic features in Parkinson's disease (PD) has not been well studied. This study addresses this issue in a prospectively designed study.

METHODS

During five years, the severity of axial symptoms, cognitive impairment, psychotic symptoms, autonomic dysfunction, depressive symptoms, and daytime sleepiness was annually evaluated in PD patients. For each domain a linear mixed-effect model was used to examine changes during follow-up and relations with age and death.

RESULTS

Of 378 included patients, 43 died during follow-up. Higher age was associated with increased severity of all nondopaminergic features except depression, and with a higher rate of progression of axial symptoms and cognitive impairment. Patients who died during follow-up had a higher severity of all nondopaminergic features except autonomic dysfunction, and a higher rate of progression of axial symptoms, cognitive impairment, and psychotic symptoms, compared to patients who survived.

CONCLUSION

This study shows that the severity of most nondopaminergic features and the progression rate of axial and psychotic symptoms and cognitive impairment increase before PD patients die, independent of the influence of age. An interaction between age and approaching death did not have a significant effect on the course of the symptoms. Improving our understanding of the fundamental biology underlying these factors and the interaction with factors intrinsic to the disease, may have profound implications for the treatment of PD.

Effect of birth size and catch-up growth on adult blood pressure and carotid intima-media thickness

AIMS

To investigate the effect of birth size and weight gain during childhood on blood pressure and carotid intima-media thickness (cIMT) in young adulthood.

METHODS

The relationship of birth size with systolic blood pressure (SBP), diastolic blood pressure (DBP), and cIMT was investigated in 243 adults, aged 18–24 years. SBP, DBP, and cIMT were also analyzed in 4 subgroups: subjects either born small for gestational age with short stature (SGA-S) or with catch-up growth (SGA-CU), or born appropriate for gestational age with idiopathic short stature or with normal stature (controls).

RESULTS

Adult weight SDS and fat mass were positively related to SBP and DBP, adjusted for birthweight SDS which was not related to SBP and DBP. Birth size was also not related to cIMT. Subgroup analyses showed no differences in blood pressure between subgroups, but cIMT was significantly greater in SGA-CU subjects than in controls after correction for age, gender and artery diameter. This difference became borderline significant after additional correction for smoking and SBP.

CONCLUSION

Not birth size but childhood weight gain, especially fat mass, determines young adult blood pressure. Postnatal catch-up growth appears to have a greater influence on cardiovascular disease markers than birth size.

Treatment effect modifiers for the patient education programme for Parkinson's disease

AIM

A recent randomised controlled trial showed significant benefits for Parkinson's disease (PD) caregivers' psychosocial problems and need for help and a trend towards significant improvement of patients' quality of life after participation in the Patient Education Programme for Parkinson's disease (PEPP). Large variations in change scores were found, indicating variation in benefit. The aim of this study was to search for treatment effect modifiers.

METHODS

Outcome measures were patients' quality of life [Parkinson's Disease Questionnaire (PDQ)-39] and caregivers' psychosocial burden [Belastungsfragebogen Parkinson Angehörigen kurzversion (BELA-A-k)]. Candidate treatment effect modifiers were participants' characteristics and baseline scores on psychological questionnaires (BELA-P/A-k, PDQ-39, EQ-5D, Self-rating Depression Scale) and patients' neuropsychological test scores (Mini Mental State Examination, National Adult Reading Test, Dutch version, Word Test, Behavioural Assessment of the Dysexecutive Syndrome rule shift, Trail Making Test, Stroop). Secondary analyses of data from a randomised controlled trial with 64 patients and 46 caregivers were performed using regression analyses with treatment group interaction terms.

RESULTS

No significant modifiers were found for the patients. In the caregiver group, a higher MMSE score of the patient at baseline was found to be a significant predictor of a lower BELA-A-k Bothered by score post-intervention of the caregiver.

CONCLUSIONS

A potential predictor of treatment benefit was found for caregivers of PD patients with better cognitive functioning. This study did not find treatment effect modifiers for PD patients: demographics, disease stage and time of diagnosis, cognitive functioning, level of baseline psychosocial burden, participating with or without a caregiver, and caregiver changes did not influence treatment outcome. The PEPP seems suitable for the majority of patients.

Validation of the web-based LUMINA questionnaire for recruiting large cohorts of migraineurs

Objective: To assess validity of a self-administered web-based migraine-questionnaire in diagnosing migraine aura for the use of epidemiological and genetic studies.

Methods: Self-reported migraineurs enrolled via the LUMINA website and completed a web-based questionnaire on headache and aura symptoms, after fulfilling screening criteria. Diagnoses were calculated using an algorithm based on the International Classification of Headache Disorders (ICHD-2), and semi-structured telephone-interviews were performed for final diagnoses. Logistic regression generated a prediction rule for aura. Algorithm-based diagnoses and predicted diagnoses were subsequently compared to the interview-derived diagnoses.

Results: In 1 year, we recruited 2397 migraineurs, of which 1067 were included in the validation. A seven-question subset provided higher sensitivity (86% vs. 45%), slightly lower specificity (75% vs. 95%), and similar positive predictive value (86% vs. 88%) in assessing aura when comparing with the ICHD-2-based algorithm.

Conclusions: This questionnaire is accurate and reliable in diagnosing migraine aura among self-reported migraineurs and enables detection of more aura cases with low false-positive rate.

Growth patterns during childhood and the relationship with acylation-stimulating protein

BACKGROUND/OBJECTIVES

Acylation-stimulating protein (ASP) is an adipose tissue-derived hormone, which stimulates glucose and free fatty acid (FFA) uptake into adipocytes. Changes in ASP metabolism are associated with alterations in lipid metabolism. As postnatal catch-up growth has been associated with dyslipidaemia in later life, we investigated the association between ASP and birth size, adult size and different growth patterns during childhood.

METHODS

The associations were investigated by multiple regression analyses in 285 young adults, aged 18-24. Subsequently, differences in ASP were analysed in four clinically relevant subgroups, young adults either born small for gestational age with short stature (SGA-S) or with catch-up growth (SGA-CU), or born appropriate for gestational age with idiopathic short stature (ISS) or with normal stature (controls).

RESULTS

Weight gain during childhood, particularly fat accumulation, was positively related to ASP levels in early adulthood, independent of birth size, age and gender. Foetal growth, reflected by birth size, was not related to ASP levels. Between the subgroups, no differences in ASP were found, but SGA-CU and ISS subjects had significantly higher levels of FFA.

CONCLUSION

Exaggerated weight gain during childhood, but not foetal growth, contributes to alterations in ASP metabolism, which may be associated with impaired FFA uptake and delayed triglycerides clearance. Therefore, exaggerated weight gain during childhood should be prevented.

Meta-analysis of diagnostic test accuracy studies with multiple thresholds using survival methods

Diagnostic tests play an important role in clinical practice. The objective of a diagnostic test accuracy study is to compare an experimental diagnostic test with a reference standard. The majority of these studies dichotomize test results into two categories: negative and positive. But often the underlying test results may be categorized into more than two, ordered, categories. This article concerns the situation where multiple studies have evaluated the same diagnostic test with the same multiple thresholds in a population of non-diseased and diseased individuals. Recently, bivariate meta-analysis has been proposed for the pooling of sensitivity and specificity, which are likely to be negatively correlated within studies. These ideas have been extended to the situation of diagnostic tests with multiple thresholds, leading to a multinomial model with multivariate normal between-study variation. This approach is efficient, but computer-intensive and its convergence is highly dependent on starting values. Moreover, monotonicity of the sensitivities/specificities for increasing thresholds is not guaranteed. Here, we propose a Poisson-correlated gamma frailty model, previously applied to a seemingly quite different situation, meta-analysis of paired survival curves. Since the approach is based on hazards, it guarantees monotonicity of the sensitivities/specificities for increasing thresholds. The approach is less efficient than the multinomial/normal approach. On the other hand, the Poisson-correlated gamma frailty model makes no assumptions on the relationship between sensitivity and specificity, gives consistent results, appears to be quite robust against different between-study variation models, and is computationally very fast and reliable with regard to the overall sensitivities/specificities.

Analysis of individual drug use as a time-varying determinant of exposure in prospective population-based cohort studies

In pharmaco-epidemiology, the use of drugs is the determinant of interest when studying exposure-outcome associations. The increased availability of computerized information about drug use on an individual basis has greatly facilitated analyses of drug effects on a population-based scale. It seems likely that many negative findings in the early days of pharmaco-epidemiology can be explained by non-differential misclassification because of too simple (yes/no) exposure measures. In this paper, the authors discuss the importance of an adequate definition of drug exposure in pharmaco-epidemiological research and how this time-varying determinant can be analyzed in cohort studies. To reduce the risk of non-differential misclassification, a precise definition of exposure is mandatory and it is important to distinguish the complete follow-up period of a population into mutually exclusive episodes of non-use, past use and current use for each individual. By analyzing exposure to drugs as a time-dependent variable in a Cox regression model, cohort studies with complete coverage of all filled prescriptions can provide us with valid and precise risk estimates of drug-outcome associations. However, such estimates may be biased in the presence of time-dependent confounders which are themselves affected by prior exposure.

Normal and mutant HTT interact to affect clinical severity and progression in Huntington disease

OBJECTIVE

Huntington disease (HD) is an autosomal dominant neurodegenerative disorder caused by a CAG repeat expansion in the HD gene (HTT). We aimed to assess whether interaction between CAG repeat sizes in the mutant and normal allele could affect disease severity and progression.

METHODS

Using linear regression and mixed-effects models, the influence of mutant and normal CAG repeat sizes interaction was assessed on 1) age at onset in 921 patients with HD, 2) clinical severity and progression in 512 of these patients with follow-up data available, and 3) basal ganglia volume on magnetic resonance images in 16 premanifest HD mutation carriers.

RESULTS

Normal and mutant CAG repeat sizes interacted to influence 1) age at onset (p = 0.001), 2) severity or progression of motor, cognitive, and functional, but not behavioral, symptoms in patients with HD (all p < 0.05), and 3) in premanifest subjects, basal ganglia volumes (p < 0.05). In subjects with mutant CAG expansions in the low range, increasing size of the normal repeat correlated with more severe symptoms and pathology, whereas for those subjects with expansions in the high range, increasing size of the normal repeat correlated with less severe symptoms and pathology.

CONCLUSIONS

Increasing CAG repeat size in normal HTT diminishes the association between mutant CAG repeat size and disease severity and progression in Huntington disease. The underlying mechanism may involve interaction of the polyglutamine domains of normal and mutant huntingtin (fragments) and needs further elucidation. These findings may have predictive value and are essential for the design and interpretation of future therapeutic trials.

Prevalence of subependymal giant cell tumors in patients with tuberous sclerosis and a review of the literature

BACKGROUND AND PURPOSE

To investigate the prevalence of subependymal giant cell ependymomas (SEGA) in patients with tuberous sclerosis complex (TSC).

METHODS

We performed a retrospective cross-sectional study in a cohort of 285 patients with known TSC. Institutional review board approval was obtained. We included all 214 TSC-patients who had received a contrast-enhanced computed tomography (CT) scan of the brain. The most recent scan was evaluated for SEGA and presence of hydrocephalus. Additionally, a literature search was performed, and pooled estimates of SEGA prevalence in TSC were calculated. We used descriptive statistics, two sample t-test, chi-squared-test, and meta-analysis as appropriate.

RESULTS

Computed tomography showed radiological evidence of SEGA in 43 of the 214 TSC-patients (20%); 23 of 105 men (22%) and 20 of 109 women (18%; P = .52). Average maximum tumor size was 11.4 mm (range, 4-29 mm). Patients with SEGA (mean, 31 years; range, 16-58 years) were on average younger than patients without SEGA (mean, 37 years; range, 10-72 years; P = 0.007). No association between tumor size and patient age was detected. Nine patients had bilateral SEGA. Hydrocephalus was present in six of the 43 patients (14%). Meta-analysis of reported prevalence and our current study showed that studies using radiological evidence to diagnose SEGA gave a higher pooled estimate of the prevalence of SEGA in TSC (0.16; 95% CI: 0.12, 0.21) than studies using mainly histopathological evidence of SEGA (0.09; 95% CI: 0.07, 0.12).

CONCLUSIONS

In our cohort, CT demonstrated evidence of SEGA in 20% of TSC-patients. Prevalence of SEGA in TSC is higher in studies using radiological evidence to diagnose SEGA than in studies using histopathological evidence.

Influence of birth size on body composition in early adulthood: the programming factors for growth and metabolism (PROGRAM)-study

BACKGROUND/OBJECTIVES

Several studies have investigated the relationship of birth size with fat mass and lean body mass (LBM), but the findings differed greatly due to different ways of measuring FM and LBM, different study populations and age groups. We hypothesized that birth size has no influence on adult body composition, whereas weight gain during childhood has.

METHODS

In the programming factors for growth and metabolism (PROGRAM)-study, a cohort of 312 young adults, aged 18-24 years, FM and LBM were determined by dual energy X-ray absorptiometry (DXA). Subsequently, differences in FM and LBM were analysed in four subgroups, young adults either born small for gestational age with short stature (SGA-S) or with catch-up growth (SGA-CU), or born appropriate for gestational age (AGA) with idiopathic short stature (ISS) or with normal stature (controls).

RESULTS

Age, gender, adult height SDS and adult weight SDS were significant positive determinants of FM and LBM, whereas weight gain during childhood was positively significant for FM and negatively for LBM. Birth weight SDS tended to be significant and birth length SDS was not. Weight gain during childhood was positively correlated with waist : hip ratio and trunk fat : total fat ratio. SGA-CU subjects had significantly higher FM and significantly lower LBM than controls.

CONCLUSION

Weight gain during childhood is an important determinant of body composition in young adulthood, whereas birth size is less important. In clinical practice, too much weight gain in childhood should be prevented as it results in a relatively high fat mass, especially in children with catch-up growth in weight, like SGA-CU subjects.

Weight loss in Huntington disease increases with higher CAG repeat number

OBJECTIVE

Huntington disease (HD) is a hereditary neurodegenerative disorder caused by an expanded number of CAG repeats in the huntingtin gene. A hallmark of HD is unintended weight loss, the cause of which is unknown. In order to elucidate the underlying mechanisms of weight loss in HD, we studied its relation to other disease characteristics including motor, cognitive, and behavioral disturbances and CAG repeat number.

METHODS

In 517 patients with early stage HD, we applied mixed-effects model analyses to correlate weight changes over 3 years to CAG repeat number and various components of the Unified Huntington's Disease Rating Scale (UHDRS). We also assessed the relation between CAG repeat number and body weight and caloric intake in the R6/2 mouse model of HD.

RESULTS

In patients with HD, mean body mass index decreased with -0.15 units per year (p < 0.001). However, no single UHDRS component, including motor, cognitive, and behavioral scores, was independently associated with the rate of weight loss. Patients with HD with a higher CAG repeat number had a faster rate of weight loss. Similarly, R6/2 mice with a larger CAG repeat length had a lower body weight, whereas caloric intake increased with larger CAG repeat length.

CONCLUSIONS

Weight loss in Huntington disease (HD) is directly linked to CAG repeat length and is likely to result from a hypermetabolic state. Other signs and symptoms of HD are unlikely to contribute to weight loss in early disease stages. Elucidation of the responsible mechanisms could lead to effective energy-based therapeutics.

Fat mass and apolipoprotein E genotype influence serum lipoprotein levels in early adulthood, whereas birth size does not

BACKGROUND/OBJECTIVES

An association between an unfavorable lipid profile and low birth weight has been reported, although this association remains controversial. We hypothesized that birth size does not have any influence on serum lipid levels but fat accumulation during childhood has.

METHODS

In the PROgramming factors for GRowth And Metabolism study, a cohort of 297 young adults, aged 18-24 yr, the influence of clinical parameters on total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, lipoprotein a, and apolipoprotein (apo) A-1 and apoB was analyzed with multiple regression modeling. In addition, differences in these lipid levels and ApoE genotype prevalence were analyzed in four subgroups: young adults either born small for gestational age with short stature or with catch-up growth, or born appropriate for gestational age with idiopathic short stature or with normal stature (controls).

RESULTS

Birth length sd score (SDS) and birth weight SDS were no significant determinants of the serum lipid levels, whereas gender, ApoE genotype, adult height SDS, adult weight SDS, and fat mass were. Comparison of the subgroups showed that small for gestational age with short stature subjects had a significantly higher apoB than controls. There were no other significant differences in lipid levels or ApoE genotype prevalence among the four subgroups.

CONCLUSIONS

ApoE genotype is an important genetic determinant of lipid levels in young adulthood. Furthermore, fat accumulation during childhood significantly determines serum lipid levels, whereas birth size has no significant contribution. For public health practice, this means that parents and their children need to be informed about the risks of fat accumulation during childhood.

Testing for genetic association: a powerful score test

To study the association between a candidate gene and a complex genetic disease, Pearson's chi2 statistic can be applied to an mx2 contingency table, where the m categories correspond to m haplotypes or marker alleles. For m>2, two alternative approaches for Pearson's chi2 can be followed, which are more powerful if one haplotype or marker allele is associated. For the first approach, various 2x2 tables are formed by combining various categories and the maximum of the corresponding chi-square statistics is considered as the final statistic. The second approach takes the average over the possible associated categories by writing down an overall likelihood. For the latter approach, we propose a new score statistic, which gives more weight to haplotypes or marker alleles that are common. Since the disease allele is often not observed, the power of the various statistics depends on both the linkage disequilibrium pattern and the frequencies of the associated haplotype or marker allele in the cases and the controls. We heuristically compare various statistics within the two approaches and present the results of a simulation that compares the performance of all considered statistics. Finally, we apply the statistics to a case-control study on the association between COL2A1 gene and radiographic osteoarthritis. Our conclusion is that overall the new proposed score statistic has good power.

Influence of birth size and body composition on bone mineral density in early adulthood: the PROGRAM study

BACKGROUND/OBJECTIVES

Low bone mineral density (BMD) may lead to osteoporosis and is associated with increased fracture risk. Associations between BMD and various factors have been reported. Our objective was to investigate whether birth size, lean body mass (LBM) and fat mass (FM) are determinants of BMD of the total body (BMD(TB)) and the lumbar spine (BMD(LS)).

METHODS

In the PROgramming factors for GRowth And Metabolism (PROGRAM) study of a cohort of 312 young adults aged 18-24 years, BMD(TB) and BMD(LS) were determined by dual-energy X-ray absorptiometry (DXA). Subsequently, differences in BMD(TB) and BMD(LS) were analysed in four subgroups: young adults born small for gestational age with short stature (SGA-S) or with catch-up growth (SGA-CU), or born appropriate for gestational age (AGA) with idiopathic short stature (ISS) or with normal stature (controls).

RESULTS

Adult weight, LBM, FM and weight gain during childhood were the main positive determinants for BMD(TB) in early adulthood, whereas birth size had no influence (adjusted R(2) = 0.50). Gender, adult weight, LBM, FM and weight gain were the significant determinants of BMD(LS). In the subgroups, after correction for age, gender and adult body size, the ISS group had a significantly lower BMD(TB) than controls but there was no difference in BMD(LS) between the subgroups.

CONCLUSIONS

Prenatal growth has no significant influence on BMD(TB) and BMD(LS) in early adulthood. Gender and postnatal growth, particularly weight gain, are the main positive determinants. To achieve a normal BMD in adulthood, healthcare workers should aim for a normal weight gain in children.

Bivariate Random Effects Meta-Analysis of ROC Curves

Meta-analysis of receiver operating characteristic (ROC)-curve data is often done with fixed-effects models, which suffer many shortcomings. Some random-effects models have been proposed to execute a meta-analysis of ROC-curve data, but these models are not often used in practice. Straightforward modeling techniques for multivariate random-effects meta-analysis of ROC-curve data are needed. The 1st aim of this article is to present a practical method that addresses the drawbacks of the fixedeffects summary ROC (SROC) method of Littenberg and Moses. Sensitivities and specificities are analyzed simultaneously using a bivariate random-effects model. The 2nd aim is to show that other SROC curves can also be derived from the bivariate model through different characterizations of the estimated bivariate normal distribution. Thereby the authors show that the bivariate random-effects approach not only extends the SROC approach but also provides a unifying framework for other approaches. The authors bring the statistical meta-analysis of ROC-curve data back into a framework of relatively standard multivariate meta-analysis with random effects. The analyses were carried out using the software package SAS (Proc NLMIXED).

Semi-parametric modelling of the distribution of the baseline risk in meta-analysis

In meta-analysis of clinical trials, often meta-regression analyses are performed to explain the heterogeneity in treatment effects that usually exist between trials. A popular explanatory variable is the risk observed in the control group, the baseline risk. The relationship between the treatment effect and the baseline risk is investigated by fitting a linear model that allows randomness on the true baseline risk by assuming a normal distribution with unknown mean and variance. However, the normality assumption could be too strong to adequately describe the underlying distribution. Therefore, we developed a new semi-parametric method that relaxes the normality assumption to a more flexible and general distribution. We applied a penalized Gaussian mixture distribution to represent the baseline risk distribution. Furthermore, a bivariate hierarchical model is formulated in order to take into account the correlation between the baseline and treatment effect. To fit the proposed model, a penalized likelihood function is maximized by an Expectation Maximization (EM) algorithm. We illustrate our method on a number of simulated data sets and on a published meta-analysis data set.

Fat mass accumulation during childhood determines insulin sensitivity in early adulthood

BACKGROUND/OBJECTIVES

Low birth weight and postnatal catch-up growth have been associated with an increased risk for diabetes mellitus type II (DMII). We evaluated the contribution of birth and adult size, body composition, and waist-to-hip ratio to DMII risk factors in young adulthood.

METHODS

In a group of 136 young adults, aged 18-24 yr, insulin sensitivity and disposition index were determined by frequent sampling iv glucose tolerance test. The association of clinical parameters with these variables was analyzed with multiple regression modeling. In addition, differences in insulin sensitivity and disposition index, a measure for beta-cell function, were analyzed in four subgroups, young adults either born small for gestational age SGA with short stature (n = 25) or SGA with catch-up growth (n = 23) or born appropriate for gestational age with idiopathic short stature (n = 23) or with normal stature (controls) (n = 26).

RESULTS

Fat mass was the only significant predictor of insulin sensitivity, whereas birth length and birth weight were not significant. After correction for age, gender, and adult body size, insulin sensitivity was significantly lower in subjects born SGA with catch-up growth compared with controls. None of the variables had a significant influence on disposition index, and there was no significant difference in disposition index between the subgroups.

CONCLUSIONS

Our data show that a higher body fat mass at 21 yr is associated with reduced insulin sensitivity, independent of birth size. These findings have important implications for public health practice.

Rapid identification and antimicrobial susceptibility testing reduce antibiotic use and accelerate pathogen-directed antibiotic use

INTRODUCTION

Rapid bacterial identification and susceptibility tests can lead to earlier microbiological diagnosis and pathogen-directed, appropriate therapy. We studied whether accelerated diagnostics affected antibiotic use and patient outcomes.

PATIENTS AND METHODS

A prospective randomized clinical trial was performed over a 2-year period. Inpatients were selected on the basis of a positive culture from normally sterile body fluids and randomly assigned to either a rapid intervention arm or the control arm. The intervention arm used the Vitek 2 automated identification and susceptibility testing device, combined with direct inoculation of blood cultures. In the control arm, the Vitek 1 system inoculated from subcultures was used. Follow-up was 4 weeks after randomization.

RESULTS

A total of 1498 patients were randomized: 746 in the intervention arm and 752 in the control arm. For susceptibility testing, the rapid arm was 22 h faster than the control arm, and for identification, it was 13 h faster (P < 0.0001). In the rapid arm, antibiotic use was 6 defined daily doses lower per patient than in the control arm (P = 0.012). Whereas antibiotics were switched more in the rapid group on the day of randomization (P = 0.006), in the control group they were switched more on day two (P = 0.02). Mortality rates did not differ significantly between the two groups (17.6% versus 15.2%).

CONCLUSIONS

While rapid bacterial identification and susceptibility testing led to earlier changes and a significant reduction in antibiotic use, they did not reduce mortality.

Calculating risk changes after negative mutation test outcomes for autosomal dominant hereditary late-onset disorders

We demonstrate, in a specific scenario, the effect of negative test results from relatives in families at risk for an autosomal dominant hereditary late-onset disorder. A hypothetical pedigree, of a family at risk of Huntington's disease, was used to demonstrate the consequences for the risk status of various family members in the case where relatives have been tested, and found to be mutation negative. We argue that accurate assessment of conditional probabilities in clinical genetics is important for individuals at risk for hereditary disorders with Mendelian transmission patterns; our formulae offer the opportunity -- when simplifying assumptions are met -- to determine the changed risk status of individuals in such cases.

Food Intake of Children with Short Stature Born Small for Gestational Age before and during a Randomized GH Trial

Parents of short children born SGA often report that their children have a serious lack of appetite and a low food intake. In this study we investigated food intake, by using a standardized 7-day food questionnaire, in 88 short SGA children before start of GH treatment. The intake was compared with the recommended daily intake (RDI) of age-matched children. We also compared the food intake of GH-treated children (n=62) with randomized controls (n=26) after 1 year of GH treatment. In addition, we evaluated the effect of food intake and GH treatment on body composition and serum levels of IGF-I, IGFBP-3 and leptin. Our study shows that caloric intake, fat and carbohydrate intake of short SGA children aged 5.9 (1.6) years was significantly lower compared to the RDI for age-matched children. One year of GH treatment resulted in a significant increase of caloric, fat, carbohydrate and protein intake compared to baseline. Compared to randomized controls, caloric, carbohydrate and protein intake increased significantly after 1 year of GH treatment. Short SGA children had significantly lower SDS scores for LBM, fat mass, skinfold (SF) and BMI compared to age-matched references. They also had significantly lower serum IGF-I, IGFBP-3 and leptin levels. GH treatment resulted in a significant increase of height, LBM, BMI, IGF-I and IGFBP-3 SDS and a significant decrease of SF SDS and leptin SDS. In conclusion, our study shows that short SGA children have indeed a lower food intake than age-matched controls. During GH treatment the food intake increased significantly compared to baseline in contrast to the randomized control group.

Laparoscopic feeding jejunostomy: a systematic review

BACKGROUND

Enteral feeding devices have gained popularity since the beneficial effects of enteral nutrition have been clarified. Laparoscopic placement of a feeding jejunostomy is the most recently described enteric access route. In order to classify current surgical techniques and assess evidence on safety of laparoscopic feeding jejunostomy, a systematic review was performed.

METHODS

The electronic databases Medline, Cochrane, and Embase were searched. Reference lists were checked and requests for additional or unpublished data were sent to authors. Outcome measures were surgical technique and catheter-related complications.

RESULTS

Enteral access for feeding purposes can be effectively achieved by laparoscopic jejunostomy. Laparoscopic jejunostomy can be accomplished by either total laparoscopic or laparoscopic-aided techniques. The most experience was obtained with total laparoscopic placement. Which technique to apply should depend on the surgeon's expertise. Conversion rate is similar to other laparoscopic procedures. Complications can be serious and therefore strict patient selection should be warranted.

CONCLUSION

Laparoscopic feeding jejunostomy is a viable method to obtain enteral access with the advantages of minimally invasive surgery.

Dynamic decision analysis to determine optimal treatment duration in chronic hepatitis C

BACKGROUND

Current guidelines for stopping treatment of chronic hepatitis C are based on hepatitis C ribonucleic acid measurements at 12 and 24 weeks.

AIM

To explore an alternative approach for making individualized recommendations about treatment duration, based on simple alanine aminotransferase tests and on cost-per-cure.

METHODS

We analysed individual patient data from 13 randomized, controlled trials with interferon alone or combined with ribavirin. Using multiple logistic regression, we built a model that estimated the probability of sustained virological response for treatment durations of 24 and 48 weeks. Decisions to prolong treatment were based on an increase in probability of sustained virological response. If the increase was 10%, the cost-per-cure became decisive with a limit of 50,000.

RESULTS

Noncirrhotics with genotype 2 or 3 did not benefit when treatment was continued beyond 24 weeks. Sustained virological response rates in cirrhotic patients increased by 14-47% if treatment was continued up to 48 weeks. In noncirrhotic genotype 1 or 4 patients who had elevated alanine aminotransferase levels at week 4, the probability of sustained virological response increased by <10% if treatment was continued up to 48 weeks; the cost-per-cure for these patients would exceed 50,000.

CONCLUSION

The dynamics of alanine aminotransferase levels and cost-per-cure provides a useful alternative to determine the duration of therapy in chronic hepatitis C.

Radiocephalic wrist arteriovenous fistula for hemodialysis: meta-analysis indicates a high primary failure rate

OBJECTIVE

To improve the precision of the estimates of primary failure rates and primary and secondary 1 year patency of radial-cephalic arteriovenous fistulas (RCAVF) for hemodialysis.

DESIGN

Meta-analysis.

MATERIALS AND METHODS

A Medline search was performed of the English language medical literature between January 1970 and October 2002. Key words that were searched included radiocephalic fistula, arteriovenous shunt, Brescia-Cimino fistula and patency. Primary failure, primary and secondary patency rates were analysed using the standard mixed effects model, which allows for variability between the different studies.

RESULTS

Eight prospective and 30 retrospective studies were included. The analysis showed a pooled estimated primary failure rate of 15.3% (95% CI: 12.7-18.3%). In addition, the pooled estimated primary and secondary patency rates of 62.5% (95% CI: 54.0-70.3%) and 66.0% (95% CI: 58.2-73.0%), respectively, were calculated. Subgroup analysis concerning various study characteristics, including study year, gender and age, did not reveal statistically significant differences.

CONCLUSION

Although, the autogenous RCAVF is considered to be the primary choice for vascular access, this meta-analysis indicates a high primary failure rate and only moderate patency rates at 1 year of follow-up.

Methodology in longitudinal studies on psychological effects of predictive DNA testing: a review

In the last two decades predictive testing programs have become available for various hereditary diseases, often accompanied by follow-up studies on the psychological effects of test outcomes. The aim of this systematic literature review is to describe and evaluate the statistical methods that were used in these follow-up studies. A literature search revealed 40 longitudinal quantitative studies that met the selection criteria for the review. Fifteen studies (38%) applied adequate statistical methods. The majority, 25 studies, applied less suitable statistical techniques. Nine studies (23%) did not report on dropout rate, and 18 studies provided no characteristics of the dropouts. Thirteen out of 22 studies that should have provided data on missing values, actually reported on the missing values. It is concluded that many studies could have yielded more and better results if more appropriate methodology had been used.

Effect of smoking on global cognitive function in nondemented elderly

BACKGROUND

Contrary to early case-control studies that suggested smoking protects against Alzheimer disease (AD), recent prospective studies have shown that elderly who smoke may be at increased risk for dementia.

OBJECTIVE

To examine prospectively the effect of smoking on cognition in nondemented elderly.

METHOD

In a multicenter cohort, the European Community Concerted Action Epidemiology of Dementia (EURODEM), including the Odense, Personnes Agées Quid (Paquid), Rotterdam, and Medical Research Council: Ageing in Liverpool Project-Health Aspects (MRC ALPHA) Studies, 17,610 persons aged 65 and over were screened and examined for dementia. After an average 2.3 years of follow-up, 11,003 nondemented participants were retested. Excluding incident dementia cases and those without baseline information on smoking gave an analytical sample of 9,209 persons. Average yearly decline in Mini-Mental State Examination (MMSE) score was compared among groups, adjusting for age, sex, baseline MMSE, education, type of residence, and history of myocardial infarction or stroke.

RESULTS

MMSE score of persons who never smoked on average declined 0.03 point/year. The adjusted decline of former smokers was 0.03 point greater and of current smokers 0.13 point greater than never smokers (p < 0.001). Higher rates of decline by smoking were found in men and women, persons with and without family history of dementia, and in three of four participating studies. Higher cigarette pack-year exposure was correlated with a significantly higher rate of decline.

CONCLUSION

Smoking may accelerate cognitive decline in nondemented elderly.

Umbilical venous volume flow and fetal behavioral states in the normally developing fetus

OBJECTIVE

To determine the relationship between umbilical venous (UV) volume flow and fetal behavioral states 1F (quiet sleep) and 2F (active sleep) in normal pregnancies at 36-40 weeks of gestation.

METHODS

Fetal behavioral states were established in 17 normal pregnancies by means of combined assessment of fetal heart rate patterns (FHRP), and fetal eye and body movements. UV vessel area (mm(2)) as obtained by tracing the inner vessel area using Labview and Imaq Vision software and UV time-averaged flow velocity (mm/s Doppler) were multiplied to calculate UV volume flow (mL/min) including flow/kg fetus. The pulsatility index (PI) in the umbilical artery was also determined. In each woman, all parameters were measured between three and five times in each behavioral state. Data are reported as mean +/- 1 SD and analyzed by paired t-test.

RESULTS

No statistically significant behavioral-state-related changes were observed for UV time-averaged velocity and UV volume flow, resulting in UV volume flow/kg fetus of 69.1 +/- 14.9 mL/min*kg at 1F and 71.6 +/- 12.1 mL/min*kg at 2F (not significant). A statistically significant increase (P = 0.02) was established for UV cross-sectional area (46.4 +/- 8.6 mm(2) vs. 49.0 +/- 10.1 mm(2)) and for fetal heart rate (FHR) from 134.2 +/- 10.3 bpm in 1F to 144.2 +/- 7 bpm in 2F. Umbilical artery PI was not significantly different between the two behavioral states.

CONCLUSIONS

On the basis of high venous vessel wall compliance, the significant increase in UV cross-sectional area during fetal behavioral state 2F may be determined by a rise in mean venous pressure. The significant rise in FHR may reflect increased fetal cardiac output during state 2F while the resistance at the hepato-ductal pathway remains relatively constant with the purpose of meeting raised energy demands during the active sleep state. This is further supported by the observed trend towards an increase in UV volume flow.

Doxazosin and hydrochlorothiazide equally affect arterial wall thickness in hypertensive males with hypercholesterolaemia (the DAPHNE study). Doxazosin Atherosclerosis Progression Study in Hypertensives in the Netherlands

BACKGROUND

Observational studies suggest a synergistic effect of hypertension and hyperlipidaemia on the progression of atherosclerosis. The alpha-blocker doxazosin has favourable effects on plasma lipids, insulin resistance and blood pressure, while the diuretic hydrochlorothiazide (HCTZ) principally affects blood pressure and increases insulin resistance.

METHODS

A randomised double-blind study over 36 months was performed to compare the effects of doxazosin and HCTZ on fasting lipids and on progression of peripheral atherosclerosis. Eighty males (45 to 70 years) with peripheral atherosclerotic disease and increased cholesterol levels (5.2-8.0 mmol/l) were treated for essential hypertension with either doxazosin (n = 41) or HCTZ (n = 39). Main outcome measures were arterial intima-media thickness (IMT) of the carotid and femoral arteries and fasting lipid parameters.

RESULTS

In the doxazosin-treated group, significant changes were observed in the concentration of triglycerides (-13.7%, p < 0.01), HDLc (+25.7%, p < 0.05) and IDLc (-30.1%, P < 0.05). In the HCTZ-treated group no significant changes in plasma lipid levels were observed. On follow-up visits systolic blood pressure in the doxazosin-treated group was 6 mm higher than in the HCTZ group. Nevertheless, the groups treated with doxazosin or HCTZ showed no differential effect on IMT after three years of treatment (p = 0.8). A significant reduction of the IMT of combined carotid and femoral arterial walls was shown in both treatment groups (p < 0.005).

CONCLUSIONS

Hypertension treatment with doxazosin or HCTZ resulted in a comparable change in arterial IMT after three years, in spite of differences in effect on plasma lipids. The study emphasises the importance of blood pressure control in patients with peripheral vascular disease and hypercholesterolaemia.

Nonsteroidal antiinflammatory drugs and the risk of Alzheimer's disease

BACKGROUND

Previous studies have suggested that the use of nonsteroidal antiinflammatory drugs (NSAIDs) may help to prevent Alzheimer's disease. The results, however, are inconsistent.

METHODS

We studied the association between the use of NSAIDs and Alzheimer's disease and vascular dementia in a prospective, population-based cohort study of 6989 subjects 55 years of age or older who were free of dementia at base line, in 1991. To detect new cases of dementia, follow-up screening was performed in 1993 and 1994 and again in 1997 through 1999. The risk of Alzheimer's disease was estimated in relation to the use of NSAIDs as documented in pharmacy records. We defined four mutually exclusive categories of use: nonuse, short-term use (1 month or less of cumulative use), intermediate-term use (more than 1 but less than 24 months of cumulative use), and long-term use (24 months or more of cumulative use). Adjustments were made by Cox regression analysis for age, sex, education, smoking status, and the use or nonuse of salicylates, histamine Hz-receptor antagonists, antihypertensive agents, and hypoglycemic agents.

RESULTS

During an average follow-up period of 6.8 years, dementia developed in 394 subjects, of whom 293 had Alzheimer's disease, 56 vascular dementia, and 45 other types of dementia. The relative risk of Alzheimer's disease was 0.95 (95 percent confidence interval, 0.70 to 1.29) in subjects with short-term use of NSAIDs, 0.83 (95 percent confidence interval, 0.62 to 1.11) in those with intermediate-term use, and 0.20 (95 percent confidence interval, 0.05 to 0.83) in those with long-term use. The risk did not vary according to age. The use of NSAIDs was not associated with a reduction in the risk of vascular dementia.

CONCLUSIONS

The long-term use of NSAIDs may protect against Alzheimer's disease but not against vascular dementia.

Balloon dilation and stent implantation for treatment of femoropopliteal arterial disease: meta-analysis

PURPOSE

To perform a meta-analysis of long-term results of balloon dilation and stent implantation in the treatment of femoropopliteal arterial disease.

MATERIALS AND METHODS

The English-language literature was searched for studies published between 1993 and 2000. Inclusion criteria for articles were presentation of long-term primary patency rates, standard errors (explicitly reported or derivable), and baseline characteristics of the study population. Two reviewers independently extracted data, and discrepancies were resolved by consensus. Primary patency rates were combined by using a technique that allows adjustment for differences across study populations. Analyses were adjusted for lesion type and clinical indication.

RESULTS

Nineteen studies met the inclusion criteria, representing 923 balloon dilations and 473 stent implantations. Combined 3-year patency rates after balloon dilation were 61% (standard error, 2.2%) for stenoses and claudication, 48% (standard error, 3.3%) for occlusions and claudication, 43% (standard error, 4.1%) for stenoses and critical ischemia, and 30% (standard error, 3.7%) for occlusions and critical ischemia. The 3-year patency rates after stent implantation were 63%-66% (standard error, 4.1%) and were independent of clinical indication and lesion type. Funnel plots demonstrated an asymmetric distribution of the data points associated with stent studies.

CONCLUSION

Balloon dilation and stent implantation for claudication and stenosis yield similar long-term patency rates. For more severe femoropopliteal disease, the results of stent implantation seem more favorable. Publication bias could not be ruled out.

Incidence and progression rates of age-related maculopathy: the Rotterdam Study

PURPOSE

To describe the incidence rate of age-related macular degeneration (AMD) and the progression rates of early stages of age-related maculopathy (ARM), and to study the hierarchy of fundus features that determine progression.

METHODS

A group of 4953 subjects aged 55 years and older living in Rotterdam, The Netherlands, was studied at baseline and at 2-year follow-up to determine the incidence of neovascular and atrophic AMD. A subgroup of 1244 subjects was studied for progression of early stages of ARM. Fundus transparencies were graded for features of ARM using the International Classification System. ARM was stratified in four exclusive stages, according to type of drusen and presence of pigmentary irregularities.

RESULTS

The overall 2-year cumulative incidence of AMD was 0.2%, increasing to 1.8% in subjects of 85 years and older. Of those in the early stages, one fourth showed progression to a more severe stage. The most important predictors for progression were more than 10% of macular area covered by drusen (odds ratio [OR] 5.7, 95% confidence interval [CI] 2.9-11.3), presence of depigmentation (OR 4.0, 95% CI 2.5-6.4), and hyperpigmentation (OR 3.4, 95% CI 2.1-5.4).

CONCLUSIONS

The incidence of AMD appears to be lower in The Netherlands than in the United States. Progression of early ARM stages occurs in a distinct pattern at a stable rate, with a large area of drusen and presence of pigmentary changes as the most important predictors.