***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective : To investigate whether additional early physiotherapy after stroke improved functional recovery in stroke patients . Design : A prospect i ve , r and omized , controlled study . Setting : One stroke ward and an acute stroke unit in a large teaching hospital , southern China . Subjects : Patients with first-onset stroke consecutively admitted to the stroke centre . Interventions : One group ( n = 78 ) received additional early physiotherapy ( AEP ) for 45 minutes , five days a week for four weeks starting within the first week since stroke onset ; the routine therapy ( RT ) group ( n = 78 ) received no professional rehabilitation therapy . Main outcome measures : Glasgow Coma Scale , Mini-Mental State Examination , Fugl-Meyer Assessment of Motor Recovery , Clinical Neurological Deficit Scale and Modified Barthel Index ( MBI ) . Results : Patients from the AEP group had a high drop-out rate ( n = 28 ) , but those remaining made relatively better functional recovery at 30 days than those from the RT group if measured by MBI . Multiple linear regression analysis revealed that cognitive disturbance , aphasia , double incontinence , site of lesion and sensory impairment might affect functional recovery after stroke . Conclusions : Additional early physiotherapy might improve independence of patients after stroke but failed to show benefit in other aspects in our study . Cognitive disturbance , aphasia , double incontinence , site of lesion as well as sensory impairment might affect functional outcome after stroke OBJECTIVE To examine cognitive function in individuals with traumatic brain injury ( TBI ) prior to and after participation in an aerobic exercise training program .  DESIGN Pre-post intervention study . SETTING Medical research center . PARTICIPANTS Volunteer sample of individuals ( N=7 ) ( age , 33.3±7.9y ) with chronic nonpenetrating TBI ( injury severity : 3=mild , 4=moderate ; time since most current injury : 4.0±5.5y ) who were ambulatory . INTERVENTION Twelve weeks of supervised vigorous aerobic exercise training performed 3 times a week for 30 minutes on a treadmill . MAIN OUTCOME MEASURES Cognitive function was assessed using the Trail Making Test Part A ( TMT-A ) , Trail Making Test Part B ( TMT-B ) , and Repeatable Battery for the Assessment of Neuropsychological Status ( RBANS ) . Sleep quality and depression were measured with the Pittsburgh Sleep Quality Index ( PSQI ) and Beck Depression Inventory , version 2 ( BDI-II ) . Indices of cardiorespiratory fitness were used to examine the relation between improvements in cognitive function and cardiorespiratory fitness . RESULTS After training , improvements in cognitive function were observed with greater scores on the TMT-A ( 10.3±6.8 ; P=.007 ) , TMT-B ( 9.6±7.0 ; P=.011 ) , and RBANS total scale ( 13.3±9.3 ; P=.009 ) . No changes were observed in measures of the PSQI and BDI-II . The magnitude of cognitive improvements was also strongly related to the gains in cardiorespiratory fitness . CONCLUSIONS These findings suggest that vigorous aerobic exercise training may improve specific aspects of cognitive function in individuals with TBI and cardiorespiratory fitness gains may be a determinant of these improvements In this issue , we answer three questions with respect to loss to follow-up in a clinical trial : How important is loss to follow-up ? How is loss to follow-up calculated ? How many patients can be lost to follow-up without mistrusting the results ? 1 . How important is loss to follow-up ? The simple answer to this question is “ very important ” because loss to follow-up can severely compromise a study 's validity . Incomplete follow-up biases the results when either : The dropout rates are different between study groups ; or The patients who drop out are different from those who do not drop out . Why do these situations make a difference ? Because in each situation , those lost to follow-up often have a different prognosis than those who complete the study . For example , patients who receive treatment for cervical myelopathy may not return for follow-up because they became asymptomatic and felt no need to return to see the surgeon . Conversely , some patients may not return because they had a particularly bad outcome ( worse pain or function ) or complication , or because they died . In either case , bias can affect the validity of the inferences drawn from the study . 2 . How is loss to follow-up calculated ? There is much confusion about how to determine the proportion of patients lost to follow-up . In order to correctly calculate the follow-up rate , one needs to know the denominator . In a r and omized controlled trial ( RCT ) , the denominator for each group is the number of patients who were r and omized , not the number who received the treatment . For example , suppose we have an RCT comparing two treatment groups , Group A and Group B. The investigators evaluate 178 patients and r and omize 120 ; 61 to Group A and 59 to Group B ( Fig 1 ) . Following the figure , we note that 49 patients received treatment A and 52 received treatment B. At the final follow-up 40 were analyzed in Group A and 41 in Group B. How many were considered lost to follow-up ? Many would consider the loss to follow-up rate to be 9 ( 18 % ) of 49 in treatment A and 11 ( 21 % ) of 52 in treatment B using as the denominator only those that were treated . However , the real proportion lost to follow-up must consider those who were r and omly assigned , even if they did not receive treatment . In the present example , this is calculated as 21 ( 34 % ) of 61 for treatment A and 18 ( 31 % ) of 59 for treatment B. Fig 1 Hypothetical example of patients lost to follow-up in a r and omized controlled trial . When calculating loss to follow-up in a retrospective cohort study , all individuals receiving treatment during the study period should be used as the denominator , not just those with complete data . For example , let 's say you want to compare decompression plus lumbar fusion with decompression alone in disc herniation and the data available are all patients receiving either treatment in the last 5 years ( N = 275 ) . However , the data base from which the data are obtained is incomplete and only 190 have the necessary data available . Since the investigators stated as part of the inclusion criteria that only those patients with complete data are included , they consider the follow-up to be 100 % ( 190/190 ) . This conclusion is wrong . The denominator should include all patients who underwent the surgery irrespective of completeness of data . The follow-up rate for this example is 69 % ( 190/275 ) . 3 . How many patients can be lost to follow-up without mistrusting the results ? Some have suggested that 20 % poses serious threats to validity 1 . This may be a good rule of thumb , but keep in mind that even small proportions of patients lost to follow-up can cause significant bias 2 . One way to determine if loss to follow-up can seriously affect results is to assume a worst-case scenario with the missing data and look to see if the results would change . Here is an example : Let 's assume a multicenter study enrolled 500 patients into each arm of a study comparing artificial disc replacement ( ADR ) with fusion , and the end point is adjacent segment disease ( ASD ) . The trial numbers are found in Fig 2 . Fig 2 Hypothetical example of the effect of loss to follow-up considering a worst-case scenario . ADR indicates artificial disc replacement ; ASD , adjacent segment disease . The proportion of patients with ASD in the ADR group is half as much versus the fusion group , 25 % ( 100/400 ) compared with 50 % ( 200/400 ) . If we assume that the 100 lost to follow-up in the ADR group had ASD and the 100 lost to follow-up in the fusion group did not , then the rate of ASD in each group would be 40 % ( 200/500 ) . In this case , adopting the worst-case scenario for the intervention group with respect to those lost to follow-up causes the results to change significantly from half the rate of ASD with ADR to the same rate . When this happens , loss to follow-up can threaten the internal validity of the trial . Only when the worst case does not change the inferences derived from the results is lost to follow-up not a problem Background and Purpose — The ability of therapeutic exercise after stroke to improve daily functioning and quality of life ( QOL ) remains controversial . We examined treatment effects on these outcomes in a r and omized controlled trial ( RCT ) of  exercise  in subacute stroke survivors . Methods — This is a secondary analysis of a single-blind RCT of a 12-week program versus usual care . Baseline , post-treatment and 6-month post-treatment daily functioning and QOL were assessed by Barthel index , Functional Independence Measure , instrumental activities of daily living , Medical Outcomes Study short-form 36-item question naire ( SF-36 ) , and Stroke Impact Scale ( SIS ) . Results — Of 100 r and omized subjects , 93 completed the postintervention assessment , ( mean age 70 ; 54 % male ; 81 % white ; mean Orpington Prognostic Score 3.4 ) , and 80 had 6-month post-treatment assessment . Immediately after intervention , the intervention group improved more than usual care in SF-36 social function ( 14.0 points ; P=0.0051 ) and in SIS ( strength [ 9.2 points ; P=0.0003 ] , emotion [ 5.6 points ; P=0.0240 ] , social participation [ 6.6 points ; P=0.0488 ] , and physical function [ 5.0 points ; P=0.0145 ] ) . Treatment was marginally more effective on Barthel score ( 3.3 points ; P=0.0510 ) , SF-36 ( physical function [ 6.8 points ; P=0.0586 ] , physical role function [ 14.4 points ; P=0.0708 ] ) , and SIS upper extremity function ( 7.2 points ; P=0.0790 ) . Effects were diluted 6 months after treatment ended . Conclusion — This rehabilitation exercise program led to more rapid improvement in aspects of physical , social , and role function than usual care in persons with subacute stroke . Adherence interventions to promote continued exercise after treatment might be needed to continue benefit BACKGROUND AND PURPOSE Systematic review s and meta-analyses often include an evaluation of the method ological quality of the individual studies that have been included , and are usually conducted by at least 2 individuals . The objective of this study was to assess the method ological quality and reliability of a series of r and omized controlled trials ( RCTs ) of both pharmacological and nonpharmacological interventions by use of the 10-item Physiotherapy Evidence -Based Data base ( PEDro ) Scale . METHODS Two abstract ors independently review ed 81 RCTs assessing a variety of interventions . The Cohen kappa statistic and the intraclass correlation coefficient ( ICC ) were used to assess agreement between abstract ors . RESULTS The average total PEDro scores were 5.94 ( SD=1.43 ) for all studies combined , 6.88 ( SD=1.2 ) for pharmacological studies , and 5.29 ( SD=1.26 ) for nonpharmacological studies . The median score for pharmacological studies was significantly higher than that for nonpharmacological studies ( 7 versus 5 ) . Pair-wise kappa scores ranged from a low of .452 for concealed allocation among drug trials to perfect agreement ( 1.00 ) for r and omization and reporting of results from between-group comparisons . The ICCs associated with the cumulative PEDro score were .91 ( 95 % confidence interval [CI]=.83-.94 ) for all studies , .89 ( 95 % CI=.78-.95 ) for pharmacological studies , and .91 ( 95 % CI=.84-.952 ) for nonpharmacological studies . DISCUSSION AND CONCLUSION The method ological quality for pharmacological interventions was significantly higher than that for nonpharmacological interventions . There was good agreement between raters at an individual item level and in total PEDro scores . A lack of reporting clarity , poor organization of the report , or the failure to include salient details contributed to less-than-perfect agreement between raters While the Mini-Mental State Examination ( MMSE ) was originally developed to screen for dementia and delirium , many neurologists use this measure as a screening instrument for ' cognitive impairment ' in hospitalized stroke patients . However , the validity of the MMSE as such has never been evaluated in acute stroke . We administered the MMSE in addition to a neuropsychological examination covering six cognitive domains to 34 stroke patients ( mean interval between stroke and examination , 6.5+/-2.9 days ) and 34 healthy controls . The area under the receiver operating characteristic curve ( AUC ) was calculated in addition to the sensitivity and specificity for various cut-off points on the MMSE . Seventy percent of the patients were impaired in at least one cognitive domain . The accuracy of the MMSE  in detecting cognitive impairment was no better than chance ( AUC = 0.67 ; p = 0.13 ) . No optimum MMSE cut-off value could be identified . The MMSE is particularly insensitive to impairments in abstract reasoning , executive functioning , and visual perception/construction OBJECTIVE To examine the impact of fitness training with recently brain-injured in patients on exercise capacity and functional and psychologic outcome measures . DESIGN A r and omized controlled trial of exercise versus relaxation training for 3 months . Blind assessment s were conducted before and after the end of a 12-week training program , as well as at follow-up assessment 12 weeks posttraining . SETTING Four regional neurologic 
    Output:
    
Though well- design ed studies are still needed , the preponderance of evidence suggests a positive effect of physical exercise on global cognitive functioning , especially in the chronic stages of a brain injury .
Time after injury as well as the duration of the exercise program are mediating factors