there is likely to be an increase in the number of geriatric patients being admitted to intensive care units ( icus ) . as per the literature , the elderly patients makeup between 26% and 51% of icu admissions . committee on manpower for pulmonary and critical care societies study showed that 56% of the icu - days were used for patients over 65-year . this emphasizes the need for continued research on outcomes of intensive care for the elderly , especially in the developing south - east asian countries with constraints on resources allocated to health care . a vast data on the icu outcomes of the geriatric population in the western world is available , but the data on outcomes in icus of developing countries like india is scarce . the current study was designed to examine the age - related difference in mortality in icu patients and assess the icu treatment modalities affecting mortality in elderly patients > 65 years of age in an indian icu setting . after approval from the hospital ethics committee , a retrospective observational study was conducted in a 350 bedded tertiary care , joint commission international - accredited super - specialty hospital in india . it is a 24 bedded multi - specialty adult icu with an average of 100 admissions per month , managed by full - timer intensivists . the criterion for icu admission is not stringent and is decided by the admitting primary physician and the intensivist , based on the clinical and physiological condition of the patient . no treatment option is restricted to a specific group of patients during the icu stay . a clinical database of all consecutive icu admissions was collected retrospectively from the hospital database system for a 2-year study period from january 1 , 2011 to december 31 , 2012 . patients who were shifted from the icu towards and then readmitted in the icu were excluded from the study , that is , only the first icu admission of the patients was included . data collected included age , sex , specialty under which admitted , admitting diagnosis , apache - ii and sofa scores at the time of icu admission and the patient outcome . average length of icu stay ( alos ) was calculated from the time of admission in icu to discharge from icu or death . data were also collected for treatment modalities used during the icu stay including use of mechanical ventilation ( invasive or noninvasive ) , inotropes , hemodialysis or slow low - efficiency dialysis and tracheostomy . for the study purpose , all patients were divided into two groups : < 65 years ( control group , group c ) and > 65 years ( geriatric age group , group g ) . data were expressed as mean  standard deviation and percentages . continuous variables with the normal distribution were evaluated using parametric method student 's t - test and categorical variables using chi - square test . patient characteristics and odds ratio ( or ) and corresponding confidence intervals ( ci ) were calculated by step - wise logistic regression analysis to identify independent risk factors and control confusion effects . only the significant variables in univariate analysis were submitted to logistic regression . all significance probabilities ( p values ) presented were of the double - tailed type and values of < 0.05 were considered as statistically significant . after approval from the hospital ethics committee , a retrospective observational study was conducted in a 350 bedded tertiary care , joint commission international - accredited super - specialty hospital in india . it is a 24 bedded multi - specialty adult icu with an average of 100 admissions per month , managed by full - timer intensivists . the criterion for icu admission is not stringent and is decided by the admitting primary physician and the intensivist , based on the clinical and physiological condition of the patient . no treatment option is restricted to a specific group of patients during the icu stay . a clinical database of all consecutive icu admissions was collected retrospectively from the hospital database system for a 2-year study period from january 1 , 2011 to december 31 , 2012 . patients who were shifted from the icu towards and then readmitted in the icu were excluded from the study , that is , only the first icu admission of the patients was included . data collected included age , sex , specialty under which admitted , admitting diagnosis , apache - ii and sofa scores at the time of icu admission and the patient outcome . average length of icu stay ( alos ) was calculated from the time of admission in icu to discharge from icu or death . data were also collected for treatment modalities used during the icu stay including use of mechanical ventilation ( invasive or noninvasive ) , inotropes , hemodialysis or slow low - efficiency dialysis and tracheostomy . for the study purpose , all patients were divided into two groups : < 65 years ( control group , group c ) and > 65 years ( geriatric age group , group g ) . data were expressed as mean  standard deviation and percentages . continuous variables with the normal distribution were evaluated using parametric method student 's t - test and categorical variables using chi - square test . patient characteristics and odds ratio ( or ) and corresponding confidence intervals ( ci ) were calculated by step - wise logistic regression analysis to identify independent risk factors and control confusion effects . only the significant variables in univariate analysis were submitted to logistic regression . all significance probabilities ( p values ) presented were of the double - tailed type and values of < 0.05 were considered as statistically significant . after approval from the hospital ethics committee , a retrospective observational study was conducted in a 350 bedded tertiary care , joint commission international - accredited super - specialty hospital in india . it is a 24 bedded multi - specialty adult icu with an average of 100 admissions per month , managed by full - timer intensivists . the criterion for icu admission is not stringent and is decided by the admitting primary physician and the intensivist , based on the clinical and physiological condition of the patient . no treatment option is restricted to a specific group of patients during the icu stay . a clinical database of all consecutive icu admissions was collected retrospectively from the hospital database system for a 2-year study period from january 1 , 2011 to december 31 , 2012 . patients who were shifted from the icu towards and then readmitted in the icu were excluded from the study , that is , only the first icu admission of the patients was included . data collected included age , sex , specialty under which admitted , admitting diagnosis , apache - ii and sofa scores at the time of icu admission and the patient outcome . average length of icu stay ( alos ) was calculated from the time of admission in icu to discharge from icu or death . data were also collected for treatment modalities used during the icu stay including use of mechanical ventilation ( invasive or noninvasive ) , inotropes , hemodialysis or slow low - efficiency dialysis and tracheostomy . for the study purpose , all patients were divided into two groups : < 65 years ( control group , group c ) and > 65 years ( geriatric age group , group g ) . continuous variables with the normal distribution were evaluated using parametric method student 's t - test and categorical variables using chi - square test . patient characteristics and odds ratio ( or ) and corresponding confidence intervals ( ci ) were calculated by step - wise logistic regression analysis to identify independent risk factors and control confusion effects . only the significant variables in univariate analysis were submitted to logistic regression . all significance probabilities ( p values ) presented were of the double - tailed type and values of < 0.05 were considered as statistically significant . during the study period , a total of 2364 patients were admitted in the icu . the medical records of 47 patients were found to be incomplete , and these patients were excluded from the study . of the 2317 patients , 1101 ( 48% ) were in group c , while 1216 ( 52% ) were in group g. the average age in group c was 47.64  12.87 years while in group g was 73.8  7.15 years . male to female ratio in group c was 364 ( 33.1% ) : 737 ( 66.9% ) and in group g was 478 ( 39.3% ) : 738 ( 60.7% ) . no statistical difference was observed in the demographic profile of two groups ( p > 0.05 ) [ table 1 ] . geriatric patients were likely to be sicker at the time of admission as shown by significantly higher apache - ii scores ( 18.17  8.5 vs. 15  6.32 , p < 0.05 ) and sofa scores ( 8.01  1.3 vs. 6.06  2.18 , p < 0.05 ) . the average duration of icu stay in group c was 8.36  10.14 days , whereas in group g was 11.42  17.41 days . specialty wise distribution of the study population the overall observed icu mortality was 19.6% . on statistical analysis , no association was found between mortality and sex ratio preference in both the age groups ( p > 0.05 ) . the icu mortality rate in group c was 19.2% ( 211 deaths ) , while in group g , was 20.1% ( 244 patients ) ( p = 0.311 ) . there was no statistical difference in the frequency of treatment modalities used in two groups in the form of mechanical ventilation , hemodialysis , inotropes and tracheostomy ( p > 0.05 ) [ table 2 ] . 298 patients required ventilatory support in group c ( 27.1% ) , of which 66 ( 22% ) expired while 352 patients ( 29% ) in group g required ventilatory support , of which 108 ( 30.6% ) expired . the mortality rate was significantly higher in geriatric patients requiring mechanical ventilation than the group c patients ( p = 0.003 , or = 0.573 , 95% ci = 0.390 - 0.843 ) [ table 3 ] . predictors of mortality in geriatric age group in total , 641 patients ( 27.7% ) required inotropic support during icu stay . 298 patients ( 27.1% ) required inotropic support , of which 89 patients ( 29.8% ) died , while 343 patients ( 28% ) in group g required inotropic support , of which 128 patients died ( 37.3% ) . there was a significant difference in mortality in geriatric and control groups requiring inotropes ( p = 0.018 , or = 0.661 , 95% ci = 0.456 - 0.958 ) . in our study , 228 patients ( 10% ) required hemodialysis treatment and the mortality rate for patients requiring hemodialysis was 31% . a total of 107 patients ( 9.7% ) in group c required hemodialysis out of which 33 ( 30.8% ) expired while 111 patients ( 9.1% ) in group g underwent hemodialysis during their icu stay , of which 38 died ( 34.2% ) . no significant difference in mortality was observed in groups g and c requiring hemodialysis in icu ( p = 0.543 , or = 1.005 , 95% ci = 0.6051.67 ) . 46 patients ( 4.2% ) required tracheostomy of which 12 ( 28.6% ) died while 63 patients ( 5% ) in group g were tracheostomised during icu stay , of which 21 died ( 33% ) . the mortality rate did not differ significantly in group g and c patients requiring tracheostomy ( p = 0.155 , or = 0.649 , 95% ci = 0.3071.335 ) . the apache - ii score ( 16.42 ) and sofa score ( 6.87 ) were significantly higher in nonsurvivors in the study ( p < 0.05 ) as shown in table 4 . apache - ii and sofa scores as predictors of mortality in overall study on univariate analysis of the icu treatment modalities , it was observed that need for mechanical ventilation ( p = 0.003 ) and inotropes ( p = 0.018 ) were predictors of mortality in geriatric age group [ table 3 ] . on applying the regression model by means of multivariate analysis , it was observed that the inotropic support was the only variable that independently discriminated icu mortality ( p = 0.000 ) [ table 5 ] . in the present study in a tertiary care indian icu , we had 52% patients > 65 years , which is similar to the us data varying between 42% and 52% . in a lithunian icu also , this demographic transition in icu admissions warrants more close observation of the outcomes in geriatric patients admitted to the icus and the treatment modalities affecting the outcome . we found overall icu mortality of ~ 20% in our study subjects , with no difference between the control group and the geriatric population ( p > 0.05 ) . different studies in the literature have studied the association of age with the outcome in geriatric patients . maia found 4 times increased risk of death in patients aged > 75 years when compared with those between 60 and 74 years ( p = 0.001 ) . also had a similar observation with 39% mortality in > 75 years age group when compared with 18% in those < 65 years ( p < 0.001 ) . stein et al . in a study on 199 patients concluded that age > 76.9 years was an independent determinant of mortality ( p < 0.001 , or = 1.08 , ci 95% 1.01 - 1.16 ) . however , many other studies could not establish a positive relationship between age and mortality . in a study on elderly subjects admitted in a moroccan icu could not find an association of age with mortality . in 97 icu patients and tang , in 365 icu patients on mechanical ventilation concluded that age itself was not a predictor of mortality . van den noortgate et al . in their study in very elderly patients could not correlate age with greater in - hospital mortality . in a two - center study on 1-year outcome observed that although icu and 1-year mortality rates differed between > 65 years and < 65 years , but age was not a major contributor to the variance in outcome . de rooij et al . , in a meta - analysis from 12 prospective and retrospective studies , also concluded that it is not age per se but factors such as severity of illness and premorbid functional status that are responsible for poor prognosis . in a review by boumendil et al . , the authors commented that age itself explains only a small part of the increased hospital mortality , suggesting that specific information such as functional , cognitive , and nutritional status , as well as co - morbidities , should be collected to predict mortality in elderly icu patients . since most studies do conclude that age is not a major contributor towards mortality , so the treatment options should not vary with age . furthermore , no specific therapy should be withheld considering increasing age as a discriminating factor . boumendil et al . in his review also concluded that it is impossible to define evidence - based recommendations for icu admission of the elderly . in our study , we found no statistical difference in the treatment modalities offered to both the groups in the form of mechanical ventilation , hemodialysis , inotropic support or tracheostomy ( p > 0.05 ) [ table 3 ] . studies have reported the mortality rates in icu patients varying from 3% to 64% , depending upon the type of subjects studied . studies with lower mortality enrolled mostly surgical and / elective patients while worse results were found with nonsurgical patients . our study population comprised of a mixed medical and surgical cases and the overall mortality in both the groups corresponds approximately to that expected as per the apache - ii and sofa scores . we observed that mechanical ventilation and inotropes were significant treatment factors for icu mortality in geriatric patients . however on multivariate analysis , only inotropic support was found to be independently associated with increased mortality . mortality rate for our geriatric patients on mechanical ventilation was 44% , which is similar to the previous studies . however , one study reported 100% mortality for patients > 85 years on mechanical ventilation . in our study , we found that the odds of having survival in geriatric icu patients on mechanical ventilation is 0.573 times the young patients on ventilation . > 65 years also found the need for mechanical ventilation as an independent determinant of mortality ( p < 0.001 , or = 3.57 , ci 95% 1.2410.3 ) . rellos et al . , in oldest - old patients also observed the need for mechanical ventilation as a predictor of all - cause in - hospital mortality ( p = 0.01 ) . ip et al . in a study on 150 patients > 70 years also found mechanical ventilation as a poor prognostic indicator ( p < 0.05 ) . an association of receipt of mechanical ventilation and an increase in long - term mortality for survivors of severe sepsis has been identified in a recent study by lemay et al . van den noortgate et al . found mechanical ventilation as a factor associated with mortality (  ; p = 0.00005 ) but on multivariate analysis , similar to our findings , they also could not attribute mechanical ventilation as an independent predictor of mortality in very elderly patients . we also found that the odds of survival in geriatric patients requiring inotropic support is 0.661 times than in the younger population < 65 years ( p = 0.000 ,  coefficient = 1.221 ) . in a study on 104 patients > 85 years found inotropes as an independent risk factor in mortality (  ; p = 0.00001 , -coefficient = 0.9698 ) . in a moroccan icu also found shock as a significant risk factor predicting mortality in patients > 65 years ( or = 11.5 , ci 95% 3.7 - 35.7 , p < 0.001 ) . friedrich et al . also associated use of inotropes or vasopressors with long - term icu mortality ( or = 7.1 , 95% ci 2.619.3 ) . although various researchers have also found an association of need for hemodialysis and icu mortality , but we could not establish a correlation between the two in our study . mortality in patients requiring dialysis in our patients was 32.5% , and there was no difference in the two age groups ( p = 0.543 ) . though raised blood urea and creatinine levels have been proposed as factors affecting mortality in geriatric patients by van den noortgate et al . but on multivariate analysis , they could not be proposed as independent predictors for mortality . the dialysis outcomes and practice patterns study ( dopps ) study to assess hemodialysis practices and outcomes among elderly versus young patients on chronic hemodialysis reports 36 fold higher mortality risk in the elderly population . however , dopps study includes patients on chronic hemodialysis and hence the results can not be extrapolated for the icu population as such . romao junior in a series of 361 patients with acute renal failure ( arf ) identified the need for dialysis as a poor prognostic factor in elderly patients with arf . we found no difference in outcomes of tracheostomised patients in two age groups in our study ( p = 0.155 ) . engorgen , in a study on 228 patients over 65-year , did not observe any difference in hospital and hospice mortality in younger elderly ( 6574 years ) and older elderly ( > 75 years ) patients receiving tracheostomy for respiratory failure ( p > 0.05 ) . , in an audit of characteristics and outcomes in 168 adult icu patients with tracheostomies concluded that tracheostomy appears to be a relatively safe technique in the icu population and is not associated with adverse outcomes . frutos - vivar et al . in a vast study in 361 icus across 12 countries observed that adjusting by other variables , tracheostomy was independently related with survival in the icu ( or = 2.22 ; 95% ci , 1.72 - 2.86 ) but in - hospital mortality was similar with or without tracheostomy ( 39% vs. 40% , p = 0.65 ) . in a retrospective study by baskin et al . , of 78 elderly patients who received tracheotomies for respiratory failure demonstrated that a large proportion of elderly , severely ill patients with respiratory failure suffer poor outcomes after tracheotomy with a death rate up to 56% . hence , they concluded that more stringent criteria are necessary for performing the tracheotomy in this patient population . thus , in our study the icu mortality rates were similar regardless of the age . however , mortality rates increased in the geriatric population requiring mechanical ventilation and inotropes during icu stay . however , only inotropic support could be proposed as an independent risk factor for mortality in the geriatric population . thus , the geriatric patients requiring mechanical ventilation and inotropic support in icu should be prognosticated accordingly . first , this is a retrospective , observational study , so both internal and external validity is relative and uncertain . our analysis focused only on icu mortality , and we did not examine postdischarge mortality or long - term prognosis . although we included all consecutive icu admissions in our study population , we do not have any record of the potential differences in requests for withdrawal of treatment by age . but as shown in previous studies , treatment limitations are likely to differ according to age . it is possible that variations in mortality may be due to prognostic factors , baseline functional status and other physiological parameters , which have been found to be independent predictors of mortality and more prevalent in older patients . we did not include this information in our study as we wanted to specifically study the impact of icu treatment modalities on geriatric mortality . also , we did not assess the long - term mortality which could have modified our results . regardless , this may limit the generalization of our findings to other geographic regions and other hospital settings . first , this is a retrospective , observational study , so both internal and external validity is relative and uncertain . our analysis focused only on icu mortality , and we did not examine postdischarge mortality or long - term prognosis . although we included all consecutive icu admissions in our study population , we do not have any record of the potential differences in requests for withdrawal of treatment by age . but as shown in previous studies , treatment limitations are likely to differ according to age . it is possible that variations in mortality may be due to prognostic factors , baseline functional status and other physiological parameters , which have been found to be independent predictors of mortality and more prevalent in older patients . we did not include this information in our study as we wanted to specifically study the impact of icu treatment modalities on geriatric mortality . also , we did not assess the long - term mortality which could have modified our results . regardless , this may limit the generalization of our findings to other geographic regions and other hospital settings . first , this is a retrospective , observational study , so both internal and external validity is relative and uncertain . our analysis focused only on icu mortality , and we did not examine postdischarge mortality or long - term prognosis . although we included all consecutive icu admissions in our study population , we do not have any record of the potential differences in requests for withdrawal of treatment by age . but as shown in previous studies , treatment limitations are likely to differ according to age . it is possible that variations in mortality may be due to prognostic factors , baseline functional status and other physiological parameters , which have been found to be independent predictors of mortality and more prevalent in older patients . we did not include this information in our study as we wanted to specifically study the impact of icu treatment modalities on geriatric mortality . also , we did not assess the long - term mortality which could have modified our results . regardless , this may limit the generalization of our findings to other geographic regions and other hospital settings . the findings of the current study provide important descriptive information about the risk factors for mortality in geriatric patients requiring icu care . our findings suggest that need for mechanical ventilation and inotropic support were the icu treatment modalities associated with higher death rates in geriatric patients . the need for inotropic support during icu stay was an independent predictor of mortality in geriatric patients . . one potential use of our results would be to incorporate the risk estimates of death into a real - time prognostic model to be used in the icu when making care decisions or when conveying prognoses to patients and families . we do not believe that these methods alone should substitute for clinical judgment or should be used alone to determine the specific treatments for individual patients . further studies of the applicability of mortality estimates in geriatric patients in icu care are clearly warranted .
background : ageing being a global phenomenon , increasing number of elderly patients are admitted to intensive care units ( icu ) . 
 hence , there is a need for continued research on outcomes of icu treatment in the elderly.objectives:examine age - related difference in outcomes of geriatric icu patients . 
 analyze icu treatment modalities predicting mortality in patients > 65 years of age.materials and methods : a retrospective observational study was conducted in 2317 patients admitted in a multi - specialty icu of a tertiary care hospital over 2-year study period from january 1 , 2011 to december 31 , 2012 . 
 a clinical database was collected which included age , sex , specialty under which admitted , apache - ii and sofa scores , patient outcome , average length of icu stay , and the treatment modalities used in icu including mechanical ventilation , inotropes , hemodialysis , and tracheostomy . 
 patients were divided into two groups : < 65 years ( control group ) and > 65 years ( geriatric age group).results : the observed overall icu mortality rate in the study population was 19.6% ; no statistical difference was observed between the control and geriatric age group in overall mortality ( p > 0.05 ) . mechanical ventilation ( p = 0.003 , odds ratio [ or ] = 0.573 , 95% confidence interval [ ci ] = 0.3900.843 ) and use of inotropes ( p = 0.018 , or = 0.661 , 95% ci = 0.4560.958 ) 
 were found to be predictors of mortality in elderly population . on multivariate analysis , 
 inotropic support was found to be an independent icu treatment modality predicting mortality in the geriatric age group (  coefficient = 1.221 , p = 0.000).conclusion : intensive care unit mortality rates increased in the geriatric population requiring mechanical ventilation and inotropes during icu stay . 
 only inotropic support could be identified as independent risk factor for mortality .