Therapeutic Intervention Scoring System Scores Research Articles

Measuring Resource Use in the ICU With Computerized Therapeutic Intervention Scoring System-Based Data

In this era of health-care reform, there is increasing need to monitor and control health-care resource consumption. This requires the development of measurement tools that are practical, uniform, reproducible, and of sufficient detail to allow comparison among institutions, among select groups of patients, and among individual patients. We explored the feasibility of generating an index of resource use based on the Therapeutic Intervention Scoring System (TISS) from hospital electronic billing data. Such an index is potentially comparable across institutions, allows assessment of care at many levels, is well understood by clinicians, and captures many of the resources relevant to the ICU. We developed an automated mapping of the hospital billing database into the different items of TISS and generated computerized active TISS scores on 1,372 ICU days. The computerized score was then validated by comparison to prospectively gathered active TISS scores by trained data collectors. Eight ICUs within a university teaching institution. We studied 1,229 general medical and surgical ICU patients. None. Active TISS scores ranged from 0 to 31 points. The two scores were well correlated (R2=0.53) and highly calibrated (as assessed by regression of active TISS on mean computerized active TISS [R2=0.85]). The scores were identical on 756 days (55.6%) and differed by < or = 3 TISS points on an additional 387 (28.2%) days. Interreliability assessment suggested substantial agreement (kappa statistic=0.71). The discriminatory power of the computerized score to identify different levels of ICU resource use was excellent as assessed by area under the receiver operating characteristics curves at four threshold points (0.91, 0.87, 0.89, and 0.88). Performance of the computerized score was similar across medical, coronary, and surgical ICU patient groups. An automated algorithm can reproduce valid TISS scores from standard hospital billing data, allowing comparison of patients and groups of patients in order to better understand ICU resource use.

A Citywide Analysis of the Utilization of Common Laboratory Tests and Imaging Procedures in ICUs

To identify and discriminate between patient and institutional determinants of investigation costs in the ICU. Retrospective survey. All seven hospitals in the city of Winnipeg, Manitoba, Canada. One hundred consecutive admissions to each of 11 ICUs. Two teaching hospitals (TH1 and TH2) each have three units (medical, surgical, and coronary care), the five community hospitals (CHs) have single combined units. TH1 operates an information-based management system. Each admission was categorized as MEDICAL, SURGICAL, or CARDIAC. The frequency and cost of 17 laboratory or imaging procedures were collected for each admission. Demographic data included age, length of ICU stay, APACHE II (acute physiology and chronic health evaluation) score, therapeutic intervention scoring system (TISS) data, and ICU survival. The primary diagnosis on admission and acquisition of significant problems or complications after admission were collected. Multivariate models revealed that length of stay, TISS score, and acquisition of a problem after ICU admission were strongly associated with increased costs in all categories (p=0.0001). Admission to TH2 was associated with greater costs in all categories (p=0.0001 MEDICAL and CARDIAC; p=0.0016 SURGICAL). Admission to a CH was associated with lower cost for SURGICAL admissions (p=0.0014), but costs at CHs were not significantly lower than at TH1 for MEDICAL (p=0.18) or CARDIAC (p=0.22) admissions. ICU investigation costs vary significantly between institutions and are not always linked to patient-dependent factors. Acquisition of nosocomial and iatrogenic events during ICU admission increases costs dramatically. Costs are not necessarily greater in teaching hospitals.

Planning patient services for intermediate care units: insights based on care for intensive care unit low-risk monitor admissions.

To describe the technology and nursing services that would be required to care for intensive care unit (ICU) low-risk monitor admissions in an intermediate unit. Prospective, multicenter, inception cohort analysis. Forty U.S. hospitals with > 200 beds, including 26 hospitals that were randomly selected and 14 that volunteered for the study. A sample of 8,040 ICU patients admitted to the ICU for monitoring, who received no active life-support treatment on ICU day 1. None. Demographic, physiologic, and treatment information were obtained during ICU days 1 to 7. A previously validated multivariate equation was used to identify 6,180 monitor admissions at low (< 10%) risk for receiving active treatment during their entire ICU stay. We used daily Therapeutic intervention Scoring System (TISS) data to identify the equipment, type and amount of nursing care, and the types of active treatment that would have been used had these ICU patients been admitted to an intermediate care unit. Mean day-1 ICU TISS scores were as follows: 16.4 for all patients; 18.3 for surgical patients; and 13.5 for medical admissions. Concentrated nursing care accounted for 89% and technologic monitoring for 11% of day-1 TISS points. Surgical admissions had a 2.8-day mean ICU length of stay and received an average of 16.5 TISS points per patient per day. Medical admissions had a 2.7-day mean ICU length of stay and received an average of 12.3 TISS points per patient per day. Subsequent active life-support therapy was received by 4.4% of these ICU low-risk monitor admissions. The services received by ICU low-risk monitor admissions provide insight regarding the equipment and nursing care that might be required, and the kinds of emergencies that might occur, if these patients were cared for in medical and surgical intermediate care units. Our data suggest that if ICU low-risk monitor patients were admitted to an intermediate care unit, they would mainly require concentrated nursing care (nurse/patient ratio of 1:3 to 1:4) and limited technologic monitoring.

Seriously ill hospitalized adults: do we spend less on older patients? Support Investigators. Study to Understand Prognoses and Preference for Outcomes and Risks of Treatments.

To determine the effect of age on hospital resource use for seriously ill adults, and to explore whether age-related differences in resource use are explained by patients' severity of illness and preferences for life-extending care. Prospective cohort study. Five geographically diverse academic acute care medical centers participating in the SUPPORT Project. A total of 4301 hospitalized adults with at least one of nine serious illnesses associated with an average 6-month mortality of 50%. Resource utilization was measured using a modified version of the Therapeutic Intervention Scoring System (TISS); the performance of three invasive procedures (major surgery, dialysis, and right heart catheter placement); and estimated hospital costs. The median patient age was 65; 43% were female, and 48% died within 6 months. After adjustment for severity of illness, prior functional status, and study site, when compared with patients younger than 50, patients 80 years or older were less likely to undergo major surgery (adjusted odds ratio .46), dialysis (.19), and right heart catheter placement (.59) and had median TISS scores and estimated hospital costs that were 3.4 points and $ 71.61 lower, respectively. These differences persisted after further adjustment for patients' preferences for life-extending care. Compared with similar younger patients, seriously ill older patients receive fewer invasive procedures and hospital care that is less resource-intensive and less costly. This preferential allocation of hospital services to younger patients is not based on differences in patients' severity of illness or general preferences for life-extending care.

Diferencias de esfuerzo terapéutico en razón del nivel socioeconómico en pacientes con infarto agudo de miocardio

To assess the hypothesis of the existence of differential therapeutic effort according to the socioeconomic status of the patients admitted to the hospital by acute myocardial infarction. We study retrospectively 592 patients admitted to the intensive care units from six public hospitals from the Spanish region of Valencia, using data from two cohort studies focused on the study of in-hospital inequalities in health. The socioeconomic status was measured using the British occupational classification. The therapeutic effort predicted for the severity of illness was determined using a regression model that included the logarithm of Therapeutic Intervention Scoring System (TISS) score as the dependent variable and Simplified Acute Physiology Score (SAPS) score and Killip group as predictors. The patients whose observed TISS was 3 or more pointless than predicted were considered as infra-treated. The effect of potential confounders was controlled using unconditional logistic regression analysis. The proportion of infra-treated patients was inversely related to socioeconomic status chi 2 for tendency = 4.31, P = 0.0378). The logistic regression analysis showed a negative association between age and therapeutic effort (p < 0.0001) but not between therapeutic effort and socioeconomic status, after controlling the effect of age (p = 0.2150). Our results suggest that older patients receive less relative therapeutic effort, measured by TISS score, than younger patients. The differential therapeutic effort observed in the crude analysis seem attributable to the higher age of the patients in the lower socioeconomic strata.

Intermediate TISS

To modify the Therapeutic Intervention Scoring System (TISS) for intermediate and floor care nursing units. Prospective study. University teaching hospital. In-patients on medical and surgical nursing units. None. Intermediate TISS retains 49 Original TISS items, adds 26 Intermediate TISS items, deletes 18 Original TISS items, and reweights 10 Original TISS items. Intermediate TISS score sums up the monitoring and therapeutic modalities used within the previous 24 hrs, each of which is assigned a weighted score from 1 to 4 points. A total of 3,073 patient days for 1,013 patients were simultaneously scored for Original TISS and Intermediate TISS over a 4-month period. A random sample of 435 patients was examined to identify those patients for whom Intermediate TISS added information over and above that obtained from Original TISS. Original TISS and Intermediate TISS correlated well, regression equation: Intermediate TISS = 4.4 + 1.4 x Original TISS (r2 = .83). We identified two groups of outliers, together constituting 96 of 435 patients: a) patients whose sum of new TISS items was unusually high relative to the sum of old TISS items included those patients with diabetes mellitus, those patients receiving serial electrocardiograms to rule out myocardial infarction and patients requiring cardiac or pulmonary therapy; b) those patients whose sum of new TISS items was low relative to the sum of old TISS items were largely surgical patients outside the intensive care unit (ICU), in whom Original TISS still worked well because it had been designed for surgical ICU patients. Intermediate TISS is useful to score medical patients receiving intermediate or floor care in non-ICU nursing units within the hospital.

Postoperative utilization of critical care services by cardiac surgery: a multicenter study in the Canadian healthcare system.

To describe patterns of critical care services used after cardiac surgery and to evaluate whether variations in the process of care influence outcome. Multicenter, prospective study. A convenience sample of four cardiac surgical units: three in university-affiliated (teaching) hospitals and one in a nonteaching regional referral center. A "consecutive sample" of 335 patients after cardiac surgery in four hospitals. Data were collected regarding all cardiac surgery patients admitted to the critical care units in the four test hospitals. The critical care unit and hospital lengths of stay and survival were followed. The Therapeutic Intervention Scoring System (TISS) was used to assess the intensive care unit (ICU) interventions used during the first 24 hrs in the ICU and for the final 24 hrs before discharge from the ICU. The severity of illness on admission was assessed using the Acute Physiology and Chronic Health Evaluation (APACHE) scoring system. For patients having similar procedures (e.g., aortocoronary bypass and nonaortocoronary bypass procedures) and with similar outcome (mortality/total hospital length of stay), we found significant differences in the pattern of ICU resource utilization among hospitals. Significant (p < .05) differences in unit length of stay were related to varying factors in different hospitals. In hospital unit A, the type of procedure and preoperative chronic health status influenced unit length of stay (aortocoronary bypass 2.8 +/- 1.7 days; nonaortocoronary bypass 8.7 +/- 8.9 days) because length of stay was different for differing procedure groups. In hospital unit B, the critical care management system and lack of step-down (intermediate care) unit availability resulted in an increased unit length of stay for aortocoronary bypass patients (5.1 +/- 4.5 days) as compared with the other units (mean ICU lengths of stay of 2.8, 2.3, and 3.0 days, respectively). Unit B kept patients for monitoring purposes and had a reduced need for critical care nursing on the day of discharge (TISS = 7.5 +/- 5.5) as compared with the other units (mean TISS scores of 27.4, 23.2, and 21.5). Significant differences exist among hospitals in the same healthcare system in the utilization of critical care services for cardiac surgery. In spite of these differences, for similar patient "input," the outcome (mortality and hospital lengths of stay) appeared similar. Assessments of utilization of critical care must focus on more detailed specific issues than unit length of stay, and must include factors such as availability of intermediate care areas, the unit management system, chronic health status, and the operative procedures performed, if a utilization management process is to effect improved resource use in critical care.

Spectral analysis of heart rate variability in the sepsis syndrome.

Sympathetic and parasympathetic activity was evaluated on 39 occasions in 17 patients with the sepsis syndrome, by measurement of the variation in resting heart rate using frequency spectrum analysis. Heart rate was recorded by electrocardiography and respiratory rate by impedance plethysmography. The sepsis syndrome was established on the basis of established clinical and physiological criteria. Subjects were studied, whenever possible, during the period of sepsis and during recovery. Spectral density of the beat-to-beat heart rate was measured within the low frequency band 0.04 to 0.10 Hz (low frequency power, LFP) modulated by sympathetic and parasympathetic activity, and within a 0.12 Hz band width at the respiratory frequency mode (respiratory frequency power, RFP) modulated by parasympathetic activity. Results were expressed as the total variability (total area beneath the power spectrum), as the spectral components normalized to the total power (LFPn, RFPn) or as the ratio of LFP/RFP. During the sepsis syndrome, total heart rate variability and the sympathetically mediated component, LFPn were significantly lower than during the following recovery phase (ANOVA, p < 0.0001, p < 0.01 respectively). Both APACHE II (Acute Physiological and Chronic Health Evaluation) and TISS (Therapeutic Intervention Scoring System) scores showed an inverse correlation with total heart rate variability, logLFP, LFPn and the LFP/RFP ratio (p < 0.002 to 0.0001). Sympathetically mediated heart rate variability was significantly lower during the sepsis syndrome and was inversely proportional to disease severity.

Explaining Variability of Cost Using a Severity-of-lllness Measure for ICU Patients

Factors related to hospital resource use by intensive care unit (ICU) patients, including severity of illness at admission and intensity of therapy during the first 24 ICU hours were explored in this study. Analysis was based on 2,749 patients admitted to the general medical-surgical ICU at Baystate Medical Center, Springfield, Massachusetts, between February 1, 1983 and January 10, 1985. Resource use was indexed by hospital length of stay (LOS) adjusted for differences between ICU and other hospital days. Severity of illness was measured by the Mortality Prediction Model (MPM0), a validated predictor of outcome but not previously used to analyze resource consumption. Intensity of therapy was measured using the Therapeutic Intervention Scoring System (TISS). The 10% of patients with longest ICU stays were significantly different from the other 90% with respect to previous ICU use, MPM probability, and TISS score. Variability in resource use was analyzed using four diagnosis-related groups (DRGs) accounting for large numbers of ICU patients. The relationship between severity of illness and resource was nonlinear: as severity increased from low levels, resource use increased at a decreasing rate, reached a plateau, and eventually declined. Within each DRG, MPM0 explained a statistically significant percentage of the variability in resource use.

Determining appropriate use of an air medical program

The Therapeutic Intervention Scoring System (TISS) was evaluated as an instrument to determine appropriate use of an air medical program (AMP) from a retrospective standpoint. TISS scores of 376 consecutive patient transports to the sponsor institution were compared to two other methods of judging appropriateness of air transport: a chart review and a review of patient outcome which included length of hospital stay, need for emergent surgery, mortality rates, and Trauma Scores. Statistically significant correlations were found between the TISS and the other two methods. We concluded that the TISS is a valid instrument for use in determining the appropriateness of air medical transports. The TISS is used as a quality assurance tool during retrospective, bi-weekly patient review sessions; and follow-up on appropriate use of the helicopter is provided to referring and receiving agencies accordingly.

Validation of two scoring systems which assess the degree of physiologic instability in critically ill newborn infants.

Modifications of the Physiologic Stability Index (PSI) and Therapeutic Intervention Scoring System (TISS) were used to evaluate the physiologic stability and need for therapeutic intervention in 55 infants hospitalized in the newborn ICU. After modifying the PSI to reflect neonatal physiology, we found that PSI scores correlated significantly with TISS values (r = .75, p less than .001) and Nursing Utilization Management Intervention System (NUMIS) classifications (r = .62, p less than .001). TISS values also correlated with NUMIS scores (r = .72, p less than .001). PSI and TISS scores increased significantly with each increase in NUMIS classification (p less than .001 for all comparisons). PSI and TISS scores decreased significantly between admission and either discharge (n = 41) or day 14 of hospitalization (n = 14, p less than .001). PSI and TISS scores were greater on days 1 and 5 in infants with hyaline membrane disease when compared with infants with transient tachypnea (p less than .001). Infants with PSI scores greater than or equal to 4 and TISS scores greater than or equal to 7 on day 1 took significantly longer to achieve adequate protein-calorie intakes than infants with lower first-day scores (p less than .002). The modified PSI and the TISS scoring systems are both useful objective measurements of the degree of physiologic instability in newborn infants requiring intensive care, and both scores identify those at increased risk for nutritional morbidity.

Thyroid hormone metabolism and level of illness severity in pediatric cardiac surgery patients

To define better the temporal relationship between alterations in thyroid hormone metabolism and changes in illness severity, we studied thyroid function in 12 children preoperatively and at 2, 12, 24, 48, and 72 hours after cardiac surgery. We then compared these findings with illness severity as assessed by a modification of the Therapeutic Intervention Scoring System (TISS). All patients had significant (p less than 0.01) reduction in serum T3 (mean 35% of baseline levels) and elevation in serum rT3 (mean 237% of baseline levels) in the postoperative period. Average correlation coefficients for the combined data were as follows: TISS and T3 levels, -0.63 +/- 0.17; TISS and rT3 levels, 0.51 +/- 0.18. Examination of individual patient data normalized to preoperative T3 and rT3 levels and compared with TISS scores demonstrated a lag in alterations of serum rT3 and T3 levels relative to illness severity during recovery from cardiac surgery. We conclude (1) the euthyroid sick syndrome occurs in all pediatric cardiac surgery patients, regardless of procedure complexity, (2) changes in rT3 levels parallel but follow changes in degree of therapeutic intervention, indicating that these alterations result from, and do not cause, increasing severity of illness, (3) rT3 levels return toward normal before T3 levels, which remain low beyond the critical postoperative period, and (4) clinical indicators of illness severity are fairly well inversely correlated with T3 levels, supporting an adaptive reduction in 5'-deiodinase activity during the postoperative period.

The critically ill child in the pediatric emergency department.

A retrospective study of the charts of all critically ill patients visiting our pediatric emergency department over an 18-month period was conducted to determine age, diagnosis, time of presentation to the pediatric ED, Physiologic Stability Index (PSI) and Therapeutic Intervention Scoring System (TISS) score, and eventual outcome. Eighty percent of critically ill patients were less than 6 years old. Of these patients, 35% had neurological problems, 23% had lower airway disease, and 15% had upper airway obstruction. Forty-one percent of children presented during the day shift, 33% during the evening shift, and 26% at night. One hundred fifteen patients survived to discharge from the intensive care unit; eight patients died. A statistically significant difference in retrospectively assigned PSI scores in nonsurvivors (18.1 +/- 6.5) compared with those in survivors (5.2 +/- 3.5) was observed. There was also a statistically significant difference in retrospectively assigned TISS scores in nonsurvivors (32.4 +/- 3.2) compared with those in survivors (13.5 +/- 2.1). Implications for physicians involved in the emergency care of critically ill children and for designs of pediatric advanced life support programs are outlined.

Therapeutic intervention scoring as a measure of performance in a helicopter emergency medical services program

Helicopter emergency medical services (HEMS), which are both expensive and resource intensive, lack objective measures for system evaluation. We computed the Therapeutic Intervention Scoring System (TISS) score for all patients during six consecutive months of service in a HEMS program to assess the value of this score for measuring the performance of the program. The TISS assigns values ranging from 1 to 4 for 57 medical and surgical interventions to measure the intensity of care during a 24-hour period. The TISS was recorded for 203 patients beginning at the time HEMS transport was requested. These flights also were classified as appropriate or inappropriate, given the information available, when HEMS care was initiated and days later when diagnostic evaluation was complete. Classification was done on the basis of whether the following criteria (potentially) ensure patient survival or improve outcome: speed of transport, presence of a medically skilled flight team, or the helicopter's ability to overcome hostile environmental conditions. The mean TISS score for all patients was 21.7. One hundred thirty-two of 203 flights (65%) were thought to be medically necessary, both at the time HEMS was requested and later (mean TISS, 28.1; analysis of variance, P less than .001). Thirty-four flights (17%) were thought to be appropriate using the information available at flight time, but not after the diagnostic workup was completed (mean TISS, 10.0). Thirty-six patients (18%) did not appear to require helicopter transport at any time, and had a mean TISS of 9.0. We conclude that TISS is a useful, objective measure of the performance of a HEMS program, and it should be tested in other HEMS programs.

Validation of a physiologic stability index for use in critically ill infants and children.

We developed a physiology-based scoring system, the Physiologic Stability Index (PSI) to assess severity of acute illness in the total population of pediatric Intensive Care Unit (ICU) patients. Thirty-four variables from seven physiologic systems were chosen, and the degree of abnormality of each variable was assigned a score reflecting the clinical importance of the derangements. Validity was demonstrated by comparing PSI to hospital mortality and to two other methods that reflect severity of illness, the Clinical Classification System (CCS) and the Therapeutic Intervention Scoring System ( TISS ). Four hundred and twenty-three consecutive admissions to a multidisciplinary ICU were followed daily. Patients classified into higher CCS classes had significantly higher PSI scores (P less than 0.001), and there was a highly significant correlation (P less than 0.001) between PSI and TISS scores. The linear-logistic regression of observed mortality versus PSI was highly significant (P less than 0.0001) and provided an excellent fit. Highly significant differences between survivors and nonsurvivors were observed for PSI scores (P less than 0.001), as well as for composite slopes of the regression of PSI scores versus days of care (P less than 0.001). These data demonstrate validity of the PSI scoring system.

Severity of illness and injury in pediatric air transport

To assess severity of illness or injury in pediatric patients undergoing air transport, we prospectively evaluated 636 patients during 29 months of service. All patients were classified by age, diagnosis, and method and distance of transport. Therapeutic intervention scoring system (TISS) scores were calculated in all patients, Glasgow coma scale (GCS) scores were used in patients with altered level of consciousness, and Modified Injury Severity Scale (MISS) scores were used in patients with multiple trauma. A total of 57.5% of patients were transported by helicopter, 37.5% by fixed-wing aircraft, and 5% by ground transport. Mean distance of transport was 207 miles. Age ranged from 3 weeks to 16 years, with 45% of children under 1 year of age. Trauma (24.6%), neurologic disease (24.2%), and respiratory failure (20%) were the most common diagnoses. Eighty-one percent of patients were taken to surgery or admitted to the intensive care unit immediately on arrival at the regional children's hospital. Mean TISS score was 36.7, with 51% of patients having TISS scores greater than 30. The mean MISS score was 34.5, and 75% of patients had MISS scores greater than 25. Nineteen percent of patients had GCS scores less than or equal to 8. Overall mortality was 7%, with 9% mortality in patients with trauma versus 6.3% in nontraumatic diseases. TISS scores greater than 30, MISS scores greater than 25, and GCS scores less than or equal to 8 were associated with increased mortality (P less than .01).

Assessment of pediatric intensive care--application of the Therapeutic Intervention Scoring System.

There are few reports analyzing the results of intensive care for children. We evaluated quantitatively the amount of care required in our multidisciplinary pediatric ICU using the Therapeutic Intervention Scoring System (TISS) and assessed qualitatively the severity of illness using the Clinical Classification System (CCS). Over a 6-month period, there were 323 patients (99 CCS Class II, 83 Class III, 141 Class IV) whose overall mortality at 1-month follow-up was 10% (Class II, 0%; Class III 2%; Class IV, 23%). A strong association was obtained between CCS and TISS admission scores (Class II-TISS, 11 +/- 0.6; Class III-TISS, 20 +/- 0.8; Class IV-TISS, 38 +/- 1.0). Class IV patients had a highly significant difference between survivors (S) and nonsurvivors (NS) for admission TISS (S = 36, NS = 47, p less than 0.001) and highest TISS (S = 38, NS = 54, p less than 0.001), as well as slopes of the regression of TISS points versus days of care (S = -4.2 vs. NS = +2.3). The mortality of our Class IV patients was lower than a comparable adult population with similar TISS scores; however, the TISS regression slopes for Class IV patients were similar. We conclude that CCS and TISS are both useful for describing the pediatric intensive care patient population. TISS is particularly helpful in assessing the amount of care received as well as providing a means of evaluating severity of illness.