critical care is evolving beyond a focus on short - term survival to include interventions aimed at reducing survivors longer term complications . in this context , denehy and colleagues   conducted a novel randomized controlled trial evaluating a rehabilitation intervention starting in the icu and continuing through the outpatient setting , with longitudinal evaluations at icu and hospital discharge , and 3 , 6 and 12  month follow - up . this new study adds to existing prospective controlled trials [ 2 - 4 ] that have evaluated the effect of icu - based rehabilitation on patient outcomes . denehy and colleagues evaluated 150 patients , with an icu stay 5  days , recruited from a single 20-bed medical - surgical icu in australia . usual care physical rehabilitation versus a rehabilitation intervention , prescribed based on physiological principles and standardized physical testing , which commenced in the icu and continued in the ward and outpatient settings . the primary outcome was the 6  minute walk test ( 6mwt ) at 12  month follow - up , with secondary outcomes including physical function and quality of life measures at icu and hospital discharge , and 3 , 6 and 12  months follow - up . of the patients enrolled , 92% required intubation and mechanical ventilation , with 55% ventilated at recruitment ( icu day 5 ) . there were no major adverse events and no significant differences in primary or secondary outcomes at 3 , 6 and 12  months . the 6mwt was significantly lower in the intervention versus control group at icu discharge , which may have been due to a higher acuity of illness in the intervention group . post hoc analysis revealed that improvement in the 6mwt from icu discharge to 12  months was significantly greater in the intervention versus control group ( mean change 292  m versus 219  m ; difference 73  m ( 95% confidence interval 9 to 136 ) ) . to understand the trial results and their generalizability , it is important to examine how rehabilitation was provided in each group and the differences in rehabilitation between the two randomized groups . first , the physiological - based approach to rehabilitation prescription may help enhance reproducibility of the intervention and consistently exercise patients at a higher level . second , given survivors frequent long - lasting neuromuscular and functional impairments [ 5 - 8 ] , an intervention spanning the icu and outpatient settings may be of value . however , notably with this latter point , denehy and colleagues reported a low rate of participants completing outpatient rehabilitation sessions , with only 41% having at least 70% attendance . in terms of understanding usual care , on ten occasions during the trial there was prospective measurement of rehabilitation interventions delivered to icu patients who were not enrolled in the trial . this sampling of usual care revealed that 52% of patients were mobilized in the icu , including some mechanically ventilated patients sitting out of bed or marching in place . this description of usual care represents substantially greater rehabilitation than delivered in two prior randomized trials ( table  1 ) . for instance , in schweickert and colleagues , usual care patients received a median of 0 ( interquartile range 0 to 0 ) hours per day of physical and occupational therapy while mechanically ventilated . moreover , the intensity of usual care rehabilitation in the denehy and colleagues trial also may have been greater than in other australian icus , based on a one - day , bi - national point prevalence study that demonstrated no mechanically ventilated patients were mobilized out of bed . comparison of in - icu rehabilitation for intervention and usual care groups in prospective trials data are reported as median ( inter - quartile range ) . based on prospective measurement of pt interventions delivered to patients who were mechanically ventilated for > 48  hours at the study site icu and were not enrolled in the trial . mv mechanically ventilated , ot occupational therapy , prom passive range of movement , pt physical therapy . potentially because of a smaller difference in the dose of rehabilitation between the intervention and control groups in the denehy and colleagues trial compared to prior prospective controlled trials ( table  1 ) , this new study did not demonstrate a benefit of the novel rehabilitation intervention . however , an important issue highlighted by this trial is the need for standardized measurement and reporting of usual care rehabilitation in clinical trials . such standardization would allow a better understanding of the difference in rehabilitation intensity between the trial s randomized groups , and between the trial and prior studies . moreover , such standardization would allow readers to evaluate the generalizability of the trial s findings to their own icus , based on their local rehabilitation practice patterns . to achieve this goal and help advance rehabilitation research , investigators must discuss this issue and achieve consensus . a post hoc analysis demonstrated that patients in the intervention versus control group had a greater improvement in their 6mwt from icu discharge to 12  month follow - up . this difference may be important if it reflects a changed trajectory of recovery and translates into survivors reaching clinically meaningful outcomes sooner ( for example , earlier return to work ) . , this trial provides a novel longitudinal evaluation of physical rehabilitation delivered across the continuum of patient recovery , highlighting the importance of understanding we conclude that critically ill patients in both australia and the us ( and likely many other countries ) may benefit from the exceptional  usual care received in the investigators study site icu in melbourne , australia . ap receives support from the national institutes of health ( grant number t32hl007534 - 31 ) .
denehy and colleagues conducted a novel randomized controlled trial evaluating a rehabilitation intervention starting in the icu and continuing through the outpatient setting , with 1  year longitudinal follow - up . 
 while the intervention did not demonstrate improved patient outcomes , this study illustrates important issues regarding 
 usual care control groups in clinical trials .