NTISS Score (Neonatal Therapeutic Intervention Scoring System)

Evaluates severity of illness for neonatal therapeutic intervention.

Refer to the text below the calculator for more information.

The NTISS (Neonatal Therapeutic Intervention Scoring System) is a severity of illness index assessment for use in neonatology, a score that has proven valuable in assessing clinical outcomes and resource consumption in neonatal intensive care.

The NTISS score was created by modifying the Therapeutic Intervention Scoring System (TISS). 

42 items were deleted from the 76 original items of the TISS and 28 new items were added. Each item assigns scores from 0 to 4 for various intensive care therapies (some of which are grouped).


Surfactant administration
Endotracheal intubation
Extracorporeal membrane oxygenation


Frequent vital signs
Cardiorespiratory monitoring
Thermoregulated environment
Non-invasive oxygen monitoring
Arterial pressure monitoring
Central venous pressure monitoring
Urinary catheter
Quantitative intake and output


Indomethacin administration
Volume expansion
Vasopressor administration
Cardiopulmonary resuscitation

4Vascular access

Peripheral intravenous line
Arterial line
Central venous line


Gavage feeding
Intravenous fat emulsion
Intravenous amino acid solution
Insulin administration
Potassium infusion


Intravenous gamma globulin
Double volume exchange transfusion
Partial volume exchange transfusion
Red blood cell transfusion
Platelet transfusion
White blood cell transfusion


Transport of patient
Chest tube
Pericardial procedure

8Drug therapy

Antibiotic administration
Diuretic administration
Anticonvulsant therapy
Aminophylinne administration
Other unscheduled medication
Steroid administration (postnatal)
Potassium binding resin administration
Treatment of metabolic acidosis
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About the NTISS

The NTISS (Neonatal Therapeutic Intervention Scoring System) measures severity of illness by quantifying the intensity and complexity of care received and is a score that has proven valuable in assessing clinical outcomes and resource consumption in neonatal intensive care.

The National Therapeutic Intervention Scoring System (NTISS) was created by modifying the Therapeutic Intervention Scoring System (TISS).

42 items were deleted from the 76 original items of the TISS and 28 new items were added. Each item assigns scores from 0 to 4 for various intensive care therapies (some of which are grouped).

Item Points
Supplemental oxygen a 1
CPAP a 2
Mechanical ventilation a 3
Mechanical ventilation with muscle relaxation a 4
High-frequency ventilation a 4
Surfactant administration 1
Endotracheal intubation 2
Tracheostomy care b 1
Tracheostomy placement b 1
Extracorporeal membrane oxygenation 4
Frequent vital signs 1
Phlebotomy (5-10 blood draws) c 1
Phlebotomy (>10 blood draws) c 2
Cardiorespiratory monitoring 1
Thermoregulated environment 1
Non-invasive oxygen monitoring 1
Arterial pressure monitoring 1
Central venous pressure monitoring 1
Urinary catheter 1
Quantitative intake and output 1
Indomethacin administration 1
Volume expansion (≤15 mL/kg) d 1
Volume expansion (>15 mL/kg) d 3
Vasopressor administration (1 agent) e 2
Vasopressor administration (>1 agent) e 3
Cardiopulmonary resuscitation 4
Pacemaker on standby f 3
Pacemaker used f 4
Vascular access  
Peripheral intravenous line 1
Arterial line 2
Central venous line 2
Gavage feeding 1
Phototherapy 1
Intravenous fat emulsion 1
Intravenous amino acid solution 1
Insulin administration 2
Potassium infusion 3
Intravenous gamma globulin 1
Double volume exchange transfusion 3
Partial volume exchange transfusion 2
Red blood cell transfusion (≤15 ml/kg) g 2
Red blood cell transfusion (>15 ml/kg) g 3
Platelet transfusion 3
White blood cell transfusion 3
Transport of patient 2
Dialysis 4
Single chest tube in place h 2
Multiple chest tubes in place h 3
Thoracentesis 3
Pericardial tube in place i 4
Pericardiocentesis i 4
Minor operation j 2
Major operation j 4
Drug therapy
Antibiotic administration (≤2 agents) k 1
Antibiotic administration (>2 agents) k 2
Enteral diuretic administration l 1
Parenteral diuretic administration l 2
Anticonvulsant therapy 1
Aminophylinne administration 1
Other unscheduled medication 1
Steroid administration (postnatal) 1
Potassium binding resin administration 3
Treatment of metabolic acidosis 3

* Items with letters in parenthesis represent the variables between which only the highest scores are computed.


Instructions for administering NTISS

NTISS scores compute the most intense level for each therapy during a 24-hour period. The first scoring period usually begins on admission. It is also important to delineate during subsequent administrations of the score whether scores are based on initiation of therapy or continuation.

In the final calculations of scores for NTISS, points should be assigned only for the most intense intervention in a group of therapies.

For example, in the case of a new-born started on supplemental oxygen (during first scoring period), who was then placed on CPAP, then on mechanical ventilation. In the final score, the patient would receive points for mechanical ventilation because it is the most intense respiratory therapy received.


About the original study

In the original study by Gray et al. admission-day NTISS scores were calculated for 1643 new-borns admitted to three neonatal intensive care units (NICUs). NTISS scores ranged from 0 to 47 with a mean of 12.3 +/- 8.7 (SD).

The NTISS scores were found to have little correlation with birth weight (r = -.11) or gestational age (r = -.17) but were highly correlated with expected markers of illness severity, including mortality risk estimates by neonatal attending physicians (r = .70, P < .0001), in-hospital mortality rates (P < .05).

NTISS scores were also found to be predictive of:

  • NICU length of stay (r = .37, P < .0001);
  • Total hospital charges for survivors (r = .65, P < .0001).


Original reference

Gray JE, Richardson DK, McCormick MC, Workman-Daniels K, Goldmann DA. Neonatal Therapeutic Intervention Scoring System: A Therapy-Based Severity-Of-Illness Index. Pediatrics. 1992; 90(4):561-7.

Other references

Wua PL, Leeb WT, Leeb PL, Chen HL. Predictive Power of Serial NeonatalTherapeutic Intervention Scoring System Scores for Short-term Mortality inVery-low-birth-weight Infants. Pediatrics and Neonatology (2015)56, 108-113.

Richardson DK, Gray JE, McCormick MC, Workman K, Goldmann DA. Score for Neonatal Acute Physiology: a physiologic severity index for neonatal intensive care. Pediatrics. 1993; 91(3):617-23.

Garg B, Sharma D, Farahbakhsh N. Assessment of sickness severity of illness in neonates: review of various neonatal illness scoring systems. J Matern Fetal Neonatal Med. 2018; 31(10):1373-1380.

Specialty: Neonatology

Year Of Study: 1992

Abbreviation: NTISS

Article By: Denise Nedea

Published On: May 28, 2020

Last Checked: May 28, 2020

Next Review: May 28, 2025