Obtaining evidence by a single well-powered trial or several modestly powered trials.

There is debate whether clinical trials with suboptimal power are justified and whether results from large studies are more reliable than the (combined) results of smaller trials. We quantified the error rates for evaluations based on single conventionally powered trials (80% or 90% power) versus evaluations based on the random-effects meta-analysis of a series of smaller trials. When a treatment was assumed to have no effect but heterogeneity was present, the error rates for a single trial were increased more than 10-fold above the nominal rate, even for low heterogeneity. Conversely, for meta-analyses on a series of trials, the error rates were correct. When selective publication was present, the error rates were always increased, but they still tended to be lower for a series of trials than single trials. We conclude that evidence of efficacy based on a series of (smaller) trials, may lower the error rates compared with using a single well-powered trial. Only when both heterogeneity and selective publication can be excluded, a single trial is able to provide conclusive evidence.

Risk of Disabling Response Fluctuations and Dyskinesias for Dopamine Agonists Versus Levodopa in Parkinson's Disease.

BACKGROUND: Response fluctuations and dyskinesias develop during the use of both levodopa (LD) and dopamine agonists (DA), but may not be equally disabling. OBJECTIVE: To compare the risk and time of onset of disabling response fluctuations and dyskinesias (DRFD) among patients with Parkinson's disease (PD) who were initially treated with either LD or DA. METHODS: Open cohort study of all consecutive de-novo PD patients in routine clinical practice, included over a period of 15 years (median follow-up: 8.1 years, range 1.1-17.7), since embarking on LD or DA. Older patients and patients with more severe PD were started on LD (n = 77), younger patients on a DA (n = 50). Therapy was adjusted according to generally accepted guidelines. The primary endpoints were: the onset of response fluctuations, dyskinesias, and the moment when these complications became disabling (DRFD). RESULTS: LD-starters developed response fluctuations 0.8 years earlier than DA-starters (p = 0.07), while dyskinesias appeared around 2.5 years earlier (p = 0.003). However, the risk and time of onset of DRFD did not differ statistically between the groups (LD-starters: 60% , median interval 7.3 years, DA-starters: 52% , 6.1 years, p = 0.63). DA-starters displayed a 0.19 points lower adjusted mean improvement in motor scores than LD-starters (p = 0.002). Adjustments for age and severity of PD at start of dopaminergic therapy did not change these results. CONCLUSIONS: In routine clinical practice, the risk and time of onset of DRFD is comparable for LD-starters versus DA-starters, but motor functioning is worse in DA-starters. These results support the use of LD as initial therapy for PD.

Artistic occupations are associated with a reduced risk of Parkinson's disease.

Parkinson's disease (PD) is preceded by a premotor phase of unknown duration. Dopaminergic degeneration during this phase may lead to subtle cognitive and behavioural changes, such as decreased novelty seeking. Consequently, premotor subjects might be most comfortable in jobs that do not require optimal dopamine levels, leading to an overrepresentation in structured and predictable occupations, or an underrepresentation in artistic occupations. In a case-control study, 750 men with PD (onset ≥40 years) and 1300 healthy men completed a validated questionnaire about their lifetime occupational status. Occupations were classified using the RIASEC model. Odds ratios (ORs) were calculated for the conventional and artistic categories, both for the most recent occupation before symptom onset, and for the very first occupation. Because farming has been associated with a PD risk, ORs were calculated separately for farming. A reduced risk of PD was found for men with an artistic occupation late in life (OR 0.14, 95% CI 0.04-0.53), while an artistic first occupation did not prevent PD (OR 0.72, CI 0.32-1.59). Conventional occupations showed no increased risk (recent: OR 1.07, CI 0.70-1.64; first: OR 1.14, CI 0.77-1.71). In support of previous reports, farming was associated with an increased risk of PD (recent: OR 2.6, CI 1.4-4.6; first: OR 2.7, CI 1.6-4.5). PD patients were older than controls, but various statistical corrections for age all lead to similar results. Artistic occupations late in life are associated with a reduced risk of subsequent PD, perhaps because this reflects a better preserved dopaminergic state. No initial occupation predicted PD, suggesting that the premotor phase starts later in life.

Small studies are more heterogeneous than large ones: a meta-meta-analysis.

OBJECTIVES: Between-study heterogeneity plays an important role in random-effects models for meta-analysis. Most clinical trials are small, and small trials are often associated with larger effect sizes. We empirically evaluated whether there is also a relationship between trial size and heterogeneity (τ). STUDY DESIGN AND SETTING: We selected the first meta-analysis per intervention review of the Cochrane Database of Systematic Reviews Issues 2009-2013 with a dichotomous (n = 2,009) or continuous (n = 1,254) outcome. The association between estimated τ and trial size was evaluated across meta-analyses using regression and within meta-analyses using a Bayesian approach. Small trials were predefined as those having standard errors (SEs) over 0.2 standardized effects. RESULTS: Most meta-analyses were based on few (median 4) trials. Within the same meta-analysis, the small study τS(2) was larger than the large-study τL(2) [average ratio 2.11; 95% credible interval (1.05, 3.87) for dichotomous and 3.11 (2.00, 4.78) for continuous meta-analyses]. The imprecision of τS was larger than of τL: median SE 0.39 vs. 0.20 for dichotomous and 0.22 vs. 0.13 for continuous small-study and large-study meta-analyses. CONCLUSION: Heterogeneity between small studies is larger than between larger studies. The large imprecision with which τ is estimated in a typical small-studies' meta-analysis is another reason for concern, and sensitivity analyses are recommended.

The Hartung-Knapp-Sidik-Jonkman method for random effects meta-analysis is straightforward and considerably outperforms the standard DerSimonian-Laird method.

BACKGROUND: The DerSimonian and Laird approach (DL) is widely used for random effects meta-analysis, but this often results in inappropriate type I error rates. The method described by Hartung, Knapp, Sidik and Jonkman (HKSJ) is known to perform better when trials of similar size are combined. However evidence in realistic situations, where one trial might be much larger than the other trials, is lacking. We aimed to evaluate the relative performance of the DL and HKSJ methods when studies of different sizes are combined and to develop a simple method to convert DL results to HKSJ results. METHODS: We evaluated the performance of the HKSJ versus DL approach in simulated meta-analyses of 2-20 trials with varying sample sizes and between-study heterogeneity, and allowing trials to have various sizes, e.g. 25% of the trials being 10-times larger than the smaller trials. We also compared the number of "positive" (statistically significant at p < 0.05) findings using empirical data of recent meta-analyses with > = 3 studies of interventions from the Cochrane Database of Systematic Reviews. RESULTS: The simulations showed that the HKSJ method consistently resulted in more adequate error rates than the DL method. When the significance level was 5%, the HKSJ error rates at most doubled, whereas for DL they could be over 30%. DL, and, far less so, HKSJ had more inflated error rates when the combined studies had unequal sizes and between-study heterogeneity. The empirical data from 689 meta-analyses showed that 25.1% of the significant findings for the DL method were non-significant with the HKSJ method. DL results can be easily converted into HKSJ results. CONCLUSIONS: Our simulations showed that the HKSJ method consistently results in more adequate error rates than the DL method, especially when the number of studies is small, and can easily be applied routinely in meta-analyses. Even with the HKSJ method, extra caution is needed when there are = <5 studies of very unequal sizes.

Prognosis of metastatic breast cancer subtypes: the hormone receptor/HER2-positive subtype is associated with the most favorable outcome.

Contrary to the situation in early breast cancer, little is known about the prognostic relevance of the hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) in metastatic breast cancer. The objectives of this study were to present survival estimates and to determine the prognostic impact of breast cancer subtypes based on HR and HER2 status in a recent cohort of metastatic breast cancer patients, which is representative of current clinical practice. Patients diagnosed with metastatic breast cancer between 2007 and 2009 were included. Information regarding patient and tumor characteristics and treatment was collected. Patients were categorized in four subtypes based on the HR and HER2 status of the primary tumor: HR positive (+)/HER2 negative (-), HR+/HER2+, HR-/HER2+ and triple negative (TN). Survival was estimated using the Kaplan-Meier method. Cox proportional hazards model was used to determine the prognostic impact of breast cancer subtype, adjusted for possible confounders. Median follow-up was 21.8 months for the 815 metastatic breast cancer patients included; 66 % of patients had the HR+/HER2- subtype, 8 % the HR-/HER2+ subtype, 15 % the TN subtype and 11 % the HR+/HER2+ subtype. The longest survival was observed for the HR+/HER2+ subtype (median 34.4 months), compared to 24.8 months for the HR+/HER2- subtype, 19.8 months for the HR-/HER2+ subtype and 8.8 months for the TN subtype (P < 0.0001). In the multivariate analysis, subtype was an independent prognostic factor, as were initial site of metastases and metastatic-free interval. The HR+/HER2+ subtype was associated with the longest survival after diagnosis of distant metastases.

Cost effectiveness of primary pegfilgrastim prophylaxis in patients with breast cancer at risk of febrile neutropenia.

PURPOSE: Guidelines advise primary granulocyte colony-stimulating factor (G-CSF) prophylaxis during chemotherapy if risk of febrile neutropenia (FN) is more than 20%, but this comes with considerable costs. We investigated the incremental costs and effects between two treatment strategies of primary pegfilgrastim prophylaxis. METHODS: Our economic evaluation used a health care perspective and was based on a randomized study in patients with breast cancer with increased risk of FN, comparing primary G-CSF prophylaxis throughout all chemotherapy cycles (G-CSF 1-6 cycles) with prophylaxis during the first two cycles only (G-CSF 1-2 cycles). Primary outcome was cost effectiveness expressed as costs per patient with episodes of FN prevented. RESULTS: The incidence of FN increased from 10% in the G-CSF 1 to 6 cycles study arm (eight of 84 patients) to 36% in the G-CSF 1 to 2 cycles study arm (30 of 83 patients), whereas the mean total costs decreased from € 20,658 (95% CI, € 20,049 to € 21,247) to € 17,168 (95% CI € 16,239 to € 18,029) per patient, respectively. Chemotherapy and G-CSF determined 80% of the total costs. As expected, FN-related costs were higher in the G-CSF 1 to 2 cycles arm. The incremental cost effectiveness ratio for the G-CSF 1 to 6 cycles arm compared with the G-CSF 1 to 2 cycles arm was € 13,112 per patient with episodes of FN prevented. CONCLUSION: We conclude that G-CSF prophylaxis throughout all chemotherapy cycles is more effective, but more costly, compared with prophylaxis limited to the first two cycles. Whether G-CSF prophylaxis throughout all chemotherapy cycles is considered cost effective depends on the willingness to pay per patient with episodes of FN prevented.

Impact of falls and fear of falling on health-related quality of life in patients with Parkinson's disease.

Postural instability, recurrent falls and fear of falling are common in advanced Parkinson's disease (PD). We examined the impact of fall frequency, fear of falling, balance confidence and objectively measured balance impairment (using Tinetti's Mobility Index) on health-related quality of life (HrQoL) in PD. In 74 subjects HrQoL was assessed using the 39-item Parkinson's disease Quality of Life Questionnaire [PDQ-39]. Patients were interviewed using a validated falls questionnaire, addressing fall history, consequences of falls and fear of falling. Neurological examination included Hoehn and Yahr scale, the Unified Parkinson's disease Rating Scale and Tinetti's Mobility Index. Disease severity, age and gender explained 43% of the differences in HrQoL across patients (R2 = 0.43). The combination of these factors and each of the factors fear of falling, balance confidence and fall frequency lead to 55%, 50% and 45% of explained variation, respectively. The standardised regression coefficients of these risk factors were 0.34 (fear of falling), 0.28 (balance confidence) and 0.13 (fall frequency). This suggests that fear of falling is a more important determinant of HrQoL than actual falling. These results emphasise the importance of addressing fear of falling in the clinical management of PD, and the need for development of strategies to reduce fear of falling in intervention programs.

Integrated multidisciplinary care in Parkinson's disease: a non-randomised, controlled trial (IMPACT).

BACKGROUND: A multidisciplinary approach is thought to be the best way to manage the motor and non-motor symptoms of Parkinson's disease, but how such care should be delivered is unknown. To address this gap in knowledge, we assessed the effectiveness of an integrated multidisciplinary approach compared with usual care. METHODS: We recruited patients for our non-randomised controlled trial from six community hospitals in the Netherlands (two in regions where the integrated care intervention was available and four in control regions that administered usual care). Eligible patients were those with Parkinson's disease, aged 20-80 years, and without severe cognitive impairment or comorbidity. Patients in the intervention group were offered an individually tailored comprehensive assessment in an expert tertiary referral centre and subsequent referrals to a regional network of allied health professionals specialised in Parkinson's disease. Primary outcomes were activities of daily living (Academic Medical Center linear disability score [ALDS]) and quality of life (Parkinson's disease quality of life questionnaire [PDQL]) measured at 4, 6, and 8 months. Secondary outcomes included motor functioning (unified Parkinson's disease rating scale, part III [UPDRS III], at 4 months), caregiver burden (belastungsfragebogen Parkinson angehörigen-kurzversion [BELA-A-k] at 4 and 8 months), and costs (during whole study period). Primary analysis was by intention to treat and included scores over 4, 6, and 8 months, with correction for baseline score. The trial is registered at Clinicaltrials.gov, number NCT00518791. FINDINGS: We recruited 301 patients (150 patients in the intervention group and 151 in the control group) between August, 2007, and December, 2009, of whom 285 completed follow-up (last follow-up was July, 2010). 101 (67%) patients in the intervention group visited the expert centre; 49 (33%) opted not to visit the expert centre. The average ALDS score from months 4, 6, and 8, with correction for baseline score, was greater in the intervention group than in the control group (difference 1·3 points, 95% CI -2·1 to 2·8; corresponding raw logit score difference 0·1, 95% CI 0·003 to 0·2) as was the average PDQL score (difference 3·0 points, 0·4 to 5·6). Secondary analysis with correction for baseline disease severity showed no differences between groups for ALDS (difference 0·9 points, 95% CI -0·6 to 2·4; corresponding raw logit score difference 0·1, -0·02 to 0·3) or PDQL (difference 1·7 points, -1·2 to 4·6). Secondary outcomes did not differ between groups (UPDRS III score difference 0·6 points, 95% CI -1·4 to 2·6; BELA-A-k score difference 0·8 points, -0·2 to 1·8; cost difference €742, -€489 to €1950). INTERPRETATION: This integrated care approach offered only small benefits to patients with Parkinson's disease, and these disappeared after correction for baseline disease severity. These results suggest that different approaches are needed to achieve more substantial health benefits. FUNDING: NutsOhra Foundation, Stichting Parkinson Nederland, National Parkinson Foundation.

Primary granulocyte colony-stimulating factor prophylaxis during the first two cycles only or throughout all chemotherapy cycles in patients with breast cancer at risk for febrile neutropenia.

PURPOSE: Early breast cancer is commonly treated with anthracyclines and taxanes. However, combining these drugs increases the risk of myelotoxicity and may require granulocyte colony-stimulating factor (G-CSF) support. The highest incidence of febrile neutropenia (FN) and largest benefit of G-CSF during the first cycles of chemotherapy lead to questions about the effectiveness of continued use of G-CSF throughout later cycles of chemotherapy. PATIENTS AND METHODS: In a multicenter study, patients with breast cancer who were considered fit enough to receive 3-weekly polychemotherapy, but also had > 20% risk for FN, were randomly assigned to primary G-CSF prophylaxis during the first two chemotherapy cycles only (experimental arm) or to primary G-CSF prophylaxis throughout all chemotherapy cycles (standard arm). The noninferiority hypothesis was that the incidence of FN would be maximally 7.5% higher in the experimental compared with the standard arm. RESULTS: After inclusion of 167 eligible patients, the independent data monitoring committee advised premature study closure. Of 84 patients randomly assigned to G-CSF throughout all chemotherapy cycles, eight (10%) experienced an episode of FN. In contrast, of 83 patients randomly assigned to G-CSF during the first two cycles only, 30 (36%) had an FN episode (95% CI, 0.13 to 0.54), with a peak incidence of 24% in the third cycle (ie, first cycle without G-CSF prophylaxis). CONCLUSION: In patients with early breast cancer at high risk for FN, continued use of primary G-CSF prophylaxis during all chemotherapy cycles is of clinical relevance and thus cannot be abandoned.

Aging attenuates the protective effect of ischemic preconditioning against endothelial ischemia-reperfusion injury in humans.

Reperfusion is mandatory after ischemia but also triggers ischemia-reperfusion (I/R) injury. Ischemic preconditioning (IPC) can limit endothelial I/R injury. Nonetheless, translation of IPC to the clinical arena is often disappointing. Since application of IPC typically relates to older patients, efficacy of IPC may be attenuated with aging. Our objective was to examine the impact of advanced age on the ability of IPC to protect against endothelial dysfunction due to I/R injury. We included 15 healthy young (20-25 yr) and 15 older (68-77 yr) men. We examined brachial artery endothelial function using flow-mediated dilation (FMD) before and after arm I/R (induced by inflation of an upper-arm blood pressure cuff for 20 min and 15 min of reperfusion). In a randomized order, I/R was preceded by IPC or a control intervention consisting of three cycles of 5 min upper-arm cuff inflation to 220 or 20 mmHg, respectively. As a result, in young men, FMD decreased significantly after I/R (6.4 ± 2.7 to 4.4 ± 2.5%). This decrease was not present when I/R was preceded by IPC (5.9 ± 2.3 to 5.6 ± 2.5%). IPC-induced protection appeared to be significantly reduced in the elderly patients (P = 0.04). Although FMD decreased after I/R in older men (3.5 ± 1.7 to 2.5 ± 1.0%), IPC could not prevent this (3.7 ± 2.1 to 2.2 ± 1.1%). In conclusion, this study is the first to observe in humans in vivo that older age is associated with an abolished effect of IPC to protect against endothelial dysfunction after I/R in the brachial artery. This provides a possible explanation for the problematic translation of strategies that reduce I/R injury from preclinical work to the clinical arena.

Promotion of physical activity and fitness in sedentary patients with Parkinson's disease: randomised controlled trial.

OBJECTIVE: To evaluate whether a multifaceted behavioural change programme increases physical activities in patients with Parkinson's disease. DESIGN: Multicentre randomised controlled trial. SETTING: 32 community hospitals in the Netherlands, collaborating in a nationwide network (ParkinsonNet). PARTICIPANTS: 586 sedentary patients with idiopathic Parkinson's disease aged between 40 and 75 years with mild to moderate disease severity (Hoehn and Yahr stage ≤ 3). INTERVENTION: Patients were randomly assigned to the ParkFit programme or a matched general physiotherapy intervention. ParkFit is a multifaceted behavioural change programme, designed specifically to achieve an enduring increase in the level of physical activity (coaches using motivational strategies; ambulatory feedback). MAIN OUTCOME MEASURES: The primary endpoint was the level of physical activity, measured every six months with a standardised seven day recall (LASA physical activity questionnaire-LAPAQ). Secondary endpoints included two other measures of physical activity (activity diary and ambulatory activity monitor), quality of life (Parkinson's disease questionnaire-PDQ-39), and fitness (six minute walk test). RESULTS: 540 (92.2%) patients completed the primary outcome. During follow-up, overall time spent on physical activities (LAPAQ) was comparable between the groups (adjusted group difference 7%, 95% confidence interval -3 to 17%; P=0.19). Analyses of three secondary outcomes indicated increased physical activity in ParkFit patients, as suggested by the activity diary (difference 30%; P<0.001), the activity monitor (difference 12%; P<0.001), and the six minute walk test (difference 4.8 m; P=0.05). PDQ-39 did not differ between ParkFit patients and controls (difference -0.9 points; P=0.14). The number of fallers was comparable between ParkFit patients (184/299; 62%) and controls (191/287; 67%). CONCLUSIONS: The ParkFit behavioural change programme did not increase overall physical activity, as measured with the LAPAQ. The analysis of the secondary endpoints justifies further work into the possible merits of behavioural change programmes to increase physical activities in daily life in Parkinson's disease. TRIAL REGISTRATION: Clinical trials NCT00748488.

Effectiveness of occupational therapy in Parkinson's disease: study protocol for a randomized controlled trial.

BACKGROUND: Occupational therapists may have an added value in the care of patients with Parkinson's disease whose daily functioning is compromised, as well as for their immediate caregivers. Evidence for this added value is inconclusive due to a lack of rigorous studies. The aim of this trial is to evaluate the (cost) effectiveness of occupational therapy in improving daily functioning of patients with Parkinson's disease. METHODS/DESIGN: A multicenter, assessor-blinded, two-armed randomized controlled clinical trial will be conducted, with evaluations at three and six months. One hundred ninety-two home-dwelling patients with Parkinson's disease and with an occupational therapy indication will be assigned to the experimental group or to the control group (2:1). Patients and their caregivers in the experimental group will receive ten weeks of home-based occupational therapy according to recent Dutch guidelines. The intervention will be delivered by occupational therapists who have been specifically trained to treat patients according to these guidelines. Participants in the control group will not receive occupational therapy during the study period. The primary outcome for the patient is self-perceived daily functioning at three months, assessed with the Canadian Occupational Performance Measure. Secondary patient-related outcomes include: objective performance of daily activities, self-perceived satisfaction with performance in daily activities, participation, impact of fatigue, proactive coping skills, health-related quality of life, overall quality of life, health-related costs, and effectiveness at six months. All outcomes at the caregiver level will be secondary and will include self-perceived burden of care, objective burden of care, proactive coping skills, overall quality of life, and care-related costs. Effectiveness will be evaluated using a covariance analysis of the difference in outcome at three months. An economic evaluation from a societal perspective will be conducted, as well as a process evaluation. DISCUSSION: This is the first large-scale trial specifically evaluating occupational therapy in Parkinson's disease. It is expected to generate important new information about the possible added value of occupational therapy on daily functioning of patients with Parkinson's disease. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01336127.

The impact of occupational therapy in Parkinson's disease: a randomized controlled feasibility study.

AIM: To evaluate the feasibility of a randomized controlled trial including process and potential impact of occupational therapy in Parkinson's disease. DESIGN: Process and outcome were quantitatively and qualitatively evaluated in an exploratory multicentre, two-armed randomized controlled trial at three months. PARTICIPANTS: Forty-three community-dwelling patients with Parkinson's disease and difficulties in daily activities, their primary caregivers and seven occupational therapists. INTERVENTION: Ten weeks of home-based occupational therapy according to the Dutch guidelines of occupational therapy in Parkinson's disease versus no occupational therapy in the control group. MAIN MEASURES: Process evaluation measured accrual, drop-out, intervention delivery and protocol adherence. Primary outcome measures of patients assessed daily functioning: Canadian Occupational Performance Measure (COPM) and Assessment of Motor and Process Skills. Primary outcome for caregivers was caregiver burden: Zarit Burden Inventory. Participants' perspectives of the intervention were explored using questionnaires and in-depth interviews. RESULTS: Inclusion was 23% (43/189), drop-out 7% (3/43) and unblinding of assessors 33% (13/40). Full intervention protocol adherence was 74% (20/27), but only 60% (71/119) of baseline Canadian Occupational Performance Measure priorities were addressed in the intervention. The outcome measures revealed negligible to small effects in favour of the intervention group. Almost all patients and caregivers of the intervention group were satisfied with the results. They perceived: 'more grip on the situation' and used 'practical advices that make life easier'. Therapists were satisfied, but wished for a longer intervention period. CONCLUSIONS: The positive perceived impact of occupational therapy warrants a large-scale trial. Adaptations in instructions and training are needed to use the Canadian Occupational Performance Measure as primary outcome measure.

Cerebrospinal fluid amyloid-ß and phenotypic heterogeneity in de novo Parkinson's disease.

BACKGROUND: In Parkinson's disease (PD), the motor presentation characterised by postural instability/gait difficulties (PIGD) heralds accelerated motor, functional and cognitive decline, as compared with the more benign tremor-dominant (TD) variant. This makes the PIGD complex an attractive target for the discovery of prognostic biomarkers in PD. OBJECTIVE: To explore in vivo whether variability in brain amyloid-ß (Aß) metabolism affects the initial motor presentation in PD. METHODS: We quantified cerebrospinal fluid (CSF) concentrations and ratios of Aß42, Aß40 and Aß38 using a triplex immunoassay in 99 patients with de novo PD with the PIGD phenotype (n=39) or the TD phenotype (n=60). All patients underwent standardised assessments of motor and neuropsychological function and cerebral MRI. 46 age-matched normal controls served as external reference. RESULTS: Patients with PD with the PIGD phenotype had significantly reduced CSF Aß42, Aß38, Aß42/40 and Aß38/40 levels compared with patients with the TD phenotype and controls. CSF marker levels in patients with PD-TD did not differ from those in controls. Multivariate regression models demonstrated significant associations of CSF Aß markers with severity of PIGD and lower limb bradykinesia in patients with PD, independently from age, MRI white matter hyperintensities and cognition. No associations were found between CSF markers and other motor features. CONCLUSIONS: Motor heterogeneity in de novo PD independently relates to CSF Aß markers, with low levels found in patients with the PIGD presentation. This suggests that disturbed Aß metabolism has an effect on PD beyond cognition and may contribute to the variable rate of motor and functional decline in PD.

Effectiveness of multidisciplinary care for Parkinson's disease: a randomized, controlled trial.

Multidisciplinary care is considered an optimal model to manage Parkinson's disease (PD), but supporting evidence is limited. We performed a randomized, controlled trial (RCT) to establish whether a multidisciplinary/specialist team offers better outcomes, compared to stand-alone care from a general neurologist. Patients with PD were randomly allocated to an intervention group (care from a movement disorders specialist, PD nurses, and social worker) or a control group (care from general neurologists). Both interventions lasted 8 months. Clinicians and researchers were blinded for group allocation. The primary outcome was the change in quality of life (Parkinson's Disease Questionnaire; PDQ-39) from baseline to 8 months. Other outcomes were the UPDRS, depression (Montgomery-Asberg Depression Scale; MADRS), psychosocial functioning (Scales for Outcomes in Parkinson's disease-Psychosocial; SCOPA-PS), and caregiver strain (Caregiver Strain Index; CSI). Group differences were analyzed using analysis of covariance adjusted for baseline values and presence of response fluctuations. A total of 122 patients were randomized and 100 completed the study (intervention, n = 51; control, n = 49). Compared to controls, the intervention group improved significantly on PDQ-39 (difference, 3.4; 95% confidence interval [CI]: 0.5-6.2) and UPDRS motor scores (4.1; 95% CI: 0.8-7.3). UPDRS total score (5.6; 95% CI: 0.9-10.3), MADRS (3.7; 95% CI: 1.4-5.9), and SCOPA-PS (2.1; 95% CI: 0.5-3.7) also improved significantly. This RCT gives credence to a multidisciplinary/specialist team approach. We interpret these positive findings cautiously because of the limitations in study design. Further research is required to assess teams involving additional disciplines and to evaluate cost-effectiveness of integrated approaches. © 2012 Movement Disorder Society.

Outcome prediction in moderate and severe traumatic brain injury: a focus on computed tomography variables.

BACKGROUND: With this study we aimed to design validated outcome prediction models in moderate and severe traumatic brain injury (TBI) using demographic, clinical, and radiological parameters. METHODS: Seven hundred consecutive moderate or severe TBI patients were included in this observational prospective cohort study. After inclusion, clinical data were collected, initial head computed tomography (CT) scans were rated, and at 6 months outcome was determined using the extended Glasgow Outcome Scale. Multivariate binary logistic regression analysis was applied to evaluate the association between potential predictors and three different outcome endpoints. The prognostic models that resulted were externally validated in a national Dutch TBI cohort. RESULTS: In line with previous literature we identified age, pupil responses, Glasgow Coma Scale score and the occurrence of a hypotensive episode post-injury as predictors. Furthermore, several CT characteristics were associated with outcome; the aspect of the ambient cisterns being the most powerful. After external validation using Receiver Operating Characteristic (ROC) analysis our prediction models demonstrated adequate discriminative values, quantified by the area under the ROC curve, of 0.86 for death versus survival and 0.83 for unfavorable versus favorable outcome. Discriminative power was less for unfavorable outcome in survivors: 0.69. CONCLUSIONS: Outcome prediction in moderate and severe TBI might be improved using the models that were designed in this study. However, conventional demographic, clinical and CT variables proved insufficient to predict disability in surviving patients. The information that can be derived from our prediction rules is important for the selection and stratification of patients recruited into clinical TBI trials.

Meier-Gorlin syndrome: growth and secondary sexual development of a microcephalic primordial dwarfism disorder.

Meier-Gorlin syndrome (MGS) is a rare autosomal recessive disorder characterized by primordial dwarfism, microtia, and patellar aplasia/hypoplasia. Recently, mutations in the ORC1, ORC4, ORC6, CDT1, and CDC6 genes, encoding components of the pre-replication complex, have been identified. This complex is essential for DNA replication and therefore mutations are expected to impair cell proliferation and consequently could globally reduce growth. However, detailed growth characteristics of MGS patients have not been reported, and so this is addressed here through study of 45 MGS patients, the largest cohort worldwide. Here, we report that growth velocity (length) is impaired in MGS during pregnancy and first year of life, but, thereafter, height increases in paralleled normal reference centiles, resulting in a mean adult height of -4.5 standard deviations (SD). Height is dependent on ethnic background and underlying molecular cause, with ORC1 and ORC4 mutations causing more severe short stature and microcephaly. Growth hormone therapy (n = 9) was generally ineffective, though in two patients with significantly reduced IGF1 levels, growth was substantially improved by GH treatment, with 2SD and 3.8 SD improvement in height. Growth parameters for monitoring growth in future MGS patients are provided and as well we highlight that growth is disproportionately affected in certain structures, with growth related minor genital abnormalities (42%) and mammary hypoplasia (100%) frequently present, in addition to established effects on ears and patellar growth.

Development and external validation of a new PTA assessment scale.

BACKGROUND: Post-traumatic amnesia (PTA) is a key symptom of traumatic brain injury (TBI). Accurate assessment of PTA is imperative in guiding clinical decision making. Our aim was to develop and externally validate a short, examiner independent and practical PTA scale, by selecting the most discriminative items from existing scales and using a three-word memory test. METHODS: Mild, moderate and severe TBI patients and control subjects were assessed in two separate cohorts, one for derivation and one for validation, using a questionnaire comprised of items from existing PTA scales. We tested which individual items best discriminated between TBI patients and controls, represented by sensitivity and specificity. We then created our PTA scale based on these results. This new scale was externally evaluated for its discriminative value using Receiver Operating Characteristic (ROC) analysis and compared to existing PTA scales. RESULTS: The derivation cohort included 126 TBI patients and 31 control subjects; the validation cohort consisted of 132 patients and 30 controls. A set of seven items was eventually selected to comprise the new PTA scale: age, name of hospital, time, day of week, month, mode of transport and recall of three words. This scale demonstrated adequate discriminative values compared to existing PTA scales on three consecutive administrations in the validation cohort. CONCLUSION: We introduce a valid, practical and examiner independent PTA scale, which is suitable for mild TBI patients at the emergency department and yet still valuable for the follow-up of more severely injured TBI patients.

A simple sample size formula for analysis of covariance in cluster randomized trials.

For cluster randomized trials with a continuous outcome, the sample size is often calculated as if an analysis of the outcomes at the end of the treatment period (follow-up scores) would be performed. However, often a baseline measurement of the outcome is available or feasible to obtain. An analysis of covariance (ANCOVA) using both the baseline and follow-up score of the outcome will then have more power. We calculate the efficiency of an ANCOVA analysis using the baseline scores compared with an analysis on follow-up scores only. The sample size for such an ANCOVA analysis is a factor r2 smaller, where r is the correlation of the cluster means between baseline and follow-up. This correlation can be expressed in clinically interpretable parameters: the correlation between baseline and follow-up of subjects (subject autocorrelation) and that of clusters (cluster autocorrelation). Because of this, subject matter knowledge can be used to provide (range of) plausible values for these correlations, when estimates from previous studies are lacking. Depending on how large the subject and cluster autocorrelations are, analysis of covariance can substantially reduce the number of clusters needed.