Standard Outcomes
Introduction
Standard outcomes may be of help to trialists in two main ways:
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By providing definitions of outcomes which are as clear and unambiguous as possible; or by reflecting current debates when there is not a single accepted definition;
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By defining sets of the most clinically important and relevant outcomes for a particular question (such as the hypothesis of an RCT or the objectives of a systematic review) or for a particular broader topic.
We are therefore are providing the following resources on the WOMBAT Collaboration website:
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A list of terms and their definitions; and the sources of those definitions
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Sets of standard outcomes for topics or questions
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Lists of core maternal and perinatal outcomes
Terms and definitions
TERM & DEFINITION
SOURCE
COMMENTS
The Apgar score is a rapid way to assess the physical condition of newborn infants. Five characteristics – heart rate, respiratory effort, muscle tone, reflex irritability and colour – are each assessed and assigned a value of 0 to 2. The total score is the sum of the five components and score of 7 or higher indicates that a baby’s condition is good to excellent. The five minute score is regarded a better predictor of neonatal survival than the one minute score.
The Apgar score should not be used to predict neurologic development of an infant.
Identified by Devane 2007 as a core outcome for assessing maternity care interventions
ELECTRONIC FETAL MONITORING (EFM) – see also FETAL HEART RATE (FHR) MONITORING
A full description of an EFM tracing requires a qualitative and quantitative description of:
· Uterine contractions
· Baseline fetal heart rate (FHR)
· Baseline FHR variability
· Presence of accelerations
· Periodic or episodic decelerations
· Changes or trends of FHR over time
This applies to interpretation of patterns from either a direct fetal electrode detecting the fetal electrocardiogram or an external Doppler device detecting the fetal heart rate events using the autocorrelation technique.
2008 National Institute of Child Health and Human Development Workshop Report on Electronic Fetal Monitoring
An ill-defined term used when the health of the fetus is threatened for reasons such as abnormal fetal heart rate patterns and/or a lack of oxygen
Identified by Devane 2007 as a core outcome for assessing maternity care interventions
FETAL HEART RATE (FHR) MONITORING – see also ELECTRONIC FETAL MONITORING (EFM)
A normal fetal heart rate (FHR) pattern is commonly accepted to be a normal baseline rate, normal (moderate) FHR variability, the presence of accelerations and the absence of decelerations – which predicts normal fetal oxygenation. A pattern of recurrent late or variable decelerations or substantial bradycardia with absent FHR variability predicts asphyxia and risk of neurological or other damage and possibly death.
At least 50% of intrapartum fetuses fit between the two extremes of this definition, limiting its usefulness (Parer 2007).
HYPERCONTRACTILITY – see also Electronic fetal monitoring
The term hypercontractility should no longer be used
HYPERSTIMULATION – see also Electronic fetal monitoring
The term hyperstimulation should no longer be used
Approximately one-third of all preterm births have iatrogenic causes, most commonly for fetal or maternal disease
INTRAUTERINE GROWTH RESTRICTION (IUGR) – see also SMALL-FOR-GESTATIONAL AGE (SGA)
IUGR and SGA are often used interchangeably, but are not synonymous. IUGR describes a fetus that fails to reach its full growth potential because of placental dysfunction.
Wherever possible, IUGR should be used instead of SGA.
Identified by Devane 2007 as a core outcome for assessing maternity care interventions
Newborn inhalation of a mixture of meconium and amniotic fluid, either in the uterus or just after birth)
Identified by Devane 2007 as a core outcome for assessing maternity care interventions
NOSOCOMIAL INFECTION (NEONATAL)
Infective episodes occurring after 48 hours of life with:
1) Isolation of organism from one blood culture;
2) After considering clinical/laboratory evidence, the decision was made to give antibiotics to treat this organism
But not with:
1) Isolation of mixed coagulase-negative staphylococci (CoNS) or other skin flora;
2) The same blood organism isolated from blood during the previous 14 days
Definition from the Australian and New Zealand Neonatal Network (ANZNN)
Identified by Devane 2007 as a core outcome for assessing maternity care interventions
a mood disorder often accompanied by features such as loss of contact with reality, hallucinations, severe thought disturbance, and abnormal behaviour.
Identified by Devane 2007 as a core outcome for assessing maternity care interventions
SMALL-FOR-GESTATIONAL AGE (SGA) - see also INTRAUTERINE GROWTH RESTRICTION (IUGR)
SGA and IUGR are often used interchangeably, but are not synonymous. SGA is most commonly used to describe a birthweight below the 10th centile for gestational age. This definition can only be applied after birth and includes some babies who are small but of normal size.
SGA is usually classified using population birthweight centiles, which account for fetal sex and gestational age at birth; customised birthweight centiles also adjust for maternal variables (parity, ethnicity, height, weight) and may be more accurate in identifying SGA as well as growth-restricted infants. Classification using customised centiles results in SGA infants with substantially higher rates of perinatal morbidity and mortality than those classified as SGA by population centiles only, suggesting that the latter are small, but normally grown, babies.
Use IUGR instead of SGA wherever possible.
Uterine contractions are quantified as the number of contractions present in a 10-minute window, averaged over 30 minutes. Contraction frequency alone is a partial assessment of uterine activity. Other factors such as duration, intensity, and relaxation time between contractions are equally important.
Normal: ≤ 5 contractions in 10 minutes, averaged over a 30 minute window
Tachysystole: > 5 contractions in 10 minutes, averaged over a 30 minute window
Characteristics of uterine contractions:
· Tachysystole should always be qualified as to the presence or absence of associated FHR decelerations
· The term tachysystole applies to both spontaneous and stimulated labour. The clinical response to tachysystole may differ depending on whether contractions are spontaneous or stimulated.
· The terms hyperstimulation and hypercontractility are not defined and should be abandoned
2008 National Institute of Child Health and Human Development Workshop Report on Electronic Fetal Monitoring
The z score is the distance between the mean in units of standard deviations. A positive z score indicates that the value is above the mean and a negative z score indicates that the value is below the mean.
Z scores are often standardised by age and sometimes by sex. An age and sex standardised z score of 1.5 indicates that the value is 1.5 standard deviations above the mean for all children of the same age and sex in the population used to standardise the score.
Casey BM, McIntire DD, Leveno KJ. The continuing value of the Apgar score for the assessment of newborn infants. New England Journal of Medicine 2001;344(7):467-71
Devane D, Begley CM, Clarke M, Horey D, OBoyle C. Evaluating maternity care: a core set of outcome measures. Birth 2007;34(2):164-72
Gill AW on behalf of The Australian and New Zealand Neonatal Network. Analysis of neonatal nosocomial infection rates across the Australian and New Zealand Neonatal Network. Journal of Hospital Infection 2009;72:155-62
Groom KM, Poppe KK, North RA, McCowan LME. Small-for-gestational-age infants classified by customized or population birthweight centiles: impact of gestational age at delivery. American Journal of Obstetrics and Gynecology 2007;197:239-41
Kipping RR, Jago R, Lawlor DA. Obesity in children. Part 1: Epidemiology, measurement, risk factors and screening. BMJ 2008;337:992-78
Macones GA, Hankins GDV, Spong CY, Hauth J, Moore T. The 2008 National Institute of Child Health and Human Development Workshop Report on Electronic Fetal Monitoring: Update on definitions, interpretation, and research guidelines. Obstetrics and Gynecology 2008;112(3):661-6
Parer JT, Ikeda T. A framework for standardized management of intrapartum fetal heart rate patterns. American Journal of Obstetrics and Gynecology 2007;197:26-7
Standard outcomes
Gestational Diabetes (Extracted from Cochrane Reviews and selected RCTS)
Diagnosis
Gestational diabetes (as defined by individual trial)
Confirmation of gestational diabetes - as assessed by need for treatment such as diet, or insulin
Gestational diabetes (this outcome will be measured by an oral glucose tolerance test (OGTT) at 26-28 weeks gestation, which is part of routine maternal care).
Reduction in gestational diabetes as diagnosed by glucose tolerance test.Insulin
Use of insulin.
Need for insulin to control blood glucose level during gestation (yes/no).
Insulin or oral hypoglycaemia agent required to treat gestational diabetes.
Doctors/diabetes educators will determine whether insulin for optimal blood glucose control or not, based on their home blood glucose monitoring readings (results presented as a group percentage).
Time until use of insulin.
Insulin sensitivity.
Insulin resistance.
Insulin resistance using homeostasis model assessment (HOMA).Glycaemic control
Fasting glucose.
Impaired glucose tolerance.
Change in fasting and 1.5 hour postprandial glucose.
Postpartum Glucose Tolerance Test results.Screening/testing/monitoring
Gestational age at screening for gestational diabetes mellitus.
Women who screen positive and are not subsequently diagnosed with GDM.
Glycaemic control.
Changes in HbA1c.
Side effects of the testing such as vomiting and bruising.
Need for repeat testing – by the same or an alternative method.
Compliance with testing, including attendance.Diabetic complications
Diabetic ketoacidosis.
Hypoglycaemia events.Follow-up
Gestational diabetes in subsequent pregnancy.
Subsequent development type II diabetes mellitus.
Future non-insulin dependent diabetes mellitus.
Long term follow up of women including development of type II diabetes.Psychosocial
Psychological impact of treatment (assessed by psychometric testing).
Psychological impact (as defined by individual trial).
Women’s preferences.
Measures of satisfaction.
Women’s view of advice.
Women’s views of their care.
Acceptability of treatments.
Postnatal depression.
Depression.
Anxiety.
Health status.
Quality of life.
Sense of well-being.Mode of birth
Mode of birth (normal VB, operative VB, CS).
Abdominal operative delivery.
Vaginal operative delivery.
Caesarean section.
Instrumental delivery.
Delivery route.Labour
Induction of labour.
Augmentation of labour.
Preterm labour (< 37/40 gestation).Maternal mortality
Mortality.
Maternal death.Maternal morbidity
Abruption
Abruption.
Placental abruptionPerineal trauma
3rd & 4th degree perineal tears.
Any perineal trauma.
Perineal and abdominal pain after delivery.Infection
Postoperative infection.
Postpartum infection.
Use of postnatal antibiotics.
Chorioamnionitis requiring antibiotics during labour.
Inflammatory markers.Levels of amniotic fluid
Hydramnios.
Oligamnios.Blood pressure
Blood pressure.
Resting BP.
Pre-eclampsia.
Hypertension.
Hypertensive complications.
Use of antihypertensive medication.Resource use
ICU admission.
Need for antenatal hospitalisation.Cardiac complications
Pulmonary oedema.
Cardiac arrest.Respiration
Adult RDS.
Respiratory arrest.Haemorrhage
Postpartum haemorrhage.
Major postpartum haemorrhage.
Postpartum haemorrhage (≥ 500mls).
Antepartum haemorrhage requiring hospital admission.Venous thromboembolism
Deep vein thrombosis or pulmonary embolism requiring anticoagulant therapy.Blood
Coagulopathy.
Haemolysis.
Transfusion.Breastfeeding
Initiation of breastfeeding and breastfeeding at hospital discharge.
Not breast feeding at hospital.
Not breast feeding at four months postpartum.Other outcomes
Stroke.
Pooled adverse events in pregnancy.
Individual components of the primary maternal outcome.Resource use
Levels of maternal inconvenience assessed by no. of hosp. visits, no. of days in hosp., extra investigations, antenatal tests (USS, CTS, amnio).
Duration of antenatal admission.
Extra use of health care services (consultations, blood glucose monitoring, length and no. of antenatal visits, admission to hospital, midwifery, medical and dietician visits and length of nursery admission ).Costs
Costs to families – change of diet, extra antenatal visits, time off work, need for additional child care.
Cost of dietary monitoring (eg. diet journals, dietician, nurse visits etc).Maternal diet and exercise outcomes
Dietary and exercise questionnaires at trial entry, 36 weeks gestation, and four months postpartum.
Change in physical activity measured by Australian Women’s Activity Scale (AWAS).
Compliance to dietary intervention.
Weight gain during pregnancy.
Fitness.
Body composition.
Increased physical activity.
Muscle strength.BMI
BMI.
BMI greater than 25.
BMI greater than 30.
Birthweight measures
BirthweightBig babies
Birth wgt > 90th centile.
Birth wgt > 4000g.
Birth wgt > 4,500g.
Macrosomia (usually defined as birth wgt > 4000g or >90th centile).
LGA.
LGA (as defined by individual trial).
LGA (birthweight greater than or equal to 90th percentile).
Incidence of LGA (defined as birth weight above the 90th percentile for gestation and fetal sex on standardised birth weight charts).Small babies
SGA (birth wgt < 10th percentile for gestational age).
SGA (less than the 10th percentile for gestational and fetal sex on standardised birth weight charts).
Severe intrauterine growth restriction (birth weight <3rd centile for gestational age).Growth/maturity outcomes at birth
Birth weight z-score
Ponderal index (weight/cube of length).
Body composition.
Fat mass.
Length.
Head circumference.
Total body water.
Lean body mass and fat mass.
Abdominal circumference.
Chest circumference.
Arm circumference.
Knee-ankle length.
5-site skin fold thickness.Gestational age
Gestational age at birth.
Postmenstrual age.Perinatal mortality
Perinatal mortality.
Stillbirths.
Death of live born infants prior to hospital discharge.
Infant death (up to one year of life).Perinatal morbidity
Preterm birth
Preterm birth.
Preterm birth (less than 37 weeks’ gestation).Birth injury
Shoulder dystocia.
Shoulder dystocia (as defined by authors).
Birth injury (shoulder dystocia, fractured clavicle, brachial plexus injury, intracranial haemorrhage).
Birth trauma.
Traumatic delivery (intracranial haemorrhage, fracture, brachial plexus injury).
Nerve palsy.
Bone fracture.Respiration
RDS.
RDS and ventilation.
Severe RDS (defined as MAP > 10 and r FiO2 ≥ .80).
Incidence and severity of RDS.
Use of and length of mechanical ventilation.
Use of ventilation ≥ 24 hours.
Chronic lung disease (defined as need for oxygen at 36 weeks).
Need for oxygen therapy at 28 days or more of life.
Use of postnatal steroids.
Use of surfactant.
Nitric oxide for respiratory support.
Need for inotropic support.
Air leak syndrome.Infection and NEC
Infection.
NEC.
Proven NEC.
Proven systemic infection after the first 48 hours of life.
Number of episodes of proven infection.
Use of antibiotics in the first 48 hours of life.Diabetic complications
Glucose level.
Hypoglycaemia.
Hypoglycaemia (requiring treatment, as defined by individual trial).
Neonatal hypoglycaemia (no treatment required, as defined by individual trial).
Neonatal hypoglycaemia requiring treatment (defined as blood glucose <2.5 mmol/L).Hyperbilirubinemia/jaundice
Hyperbilirubinemia.
Hyperbilirubinaemia requiring treatment.
Hyperbilirubinaemia (usually defined as bilirubinaemia > 12 or 15 mg/dl).
Jaundice requiring phototherapy.Apgar
Apgar scores.
Five minute Apgar scores less than seven.
Five minute Apgar scores less than four.
Apgar score < 4 at 5 minutes.Brain anomalies
Seizures.
Seizures at < 24 hours age or requiring two or more drugs to control.
Intraventricular haemorrhage on early cranial ultrasound.
Intraventricular haemorrhage grade 3 or 4.
Periventriuclar leucomalacia.
Neonatal encephalopathy (Sarnet Stage 1, 2 or 3).ROP
Retinopathy of prematurity.
Retinopathy of prematurity grade 3 or 4.Blood
Cord blood pH < 7.0.
Cord blood biochemical profile as measured by cord blood glucose, insulin, C-peptide, adiponectin, leptin, HbA1C, C-reactive protein, insulin like growth factor-1 (IFG-1) and insulin like growth factor-1 binding protein (IGF-1 BP).
Thrombocytopania.Other outcomes
Tube feeding ≥ 4 days.
Individual components of the composite primary infant outcome.
Pooled adverse events in fetus or newborn.
PDA requiring treatment.
Asphyxia (low arterial cord blood pH, low 5 mins Apgar score, as defined by authors).
Congenital malformations.Composite of morbidity, incl.:
Hypoglycaemia.
Respiratory distress.
Prematurity.
Phototherapy.
Birth trauma.
Low Apgar.
Neonatal anthropometry.
Cord blood measure of adipoinsular axis.Composite morbidity:
Hypoglycaemia.
Hyperinsulinemia.
Hyperbilirubinemia.
Birth trauma.
Death or stillbirth.Resource use
Admission to NICU or SCBU & length of stay.
Care in NICU > 4 days.
Admission to neonatal ward.
LOS in neonatal ward.
Need for admission to the neonatal surgery and length of stay.Childhood
Body composition
BMI.
BMI greater than 25.
BMI greater than 30.
Weight.
Height.
Fat mass/ fat free mass.
Skinfold thickness measurements.Diabetes
Impaired glucose tolerance.
Type I diabetes.
Type II diabetes.
Insulin sensitivity.
Dyslipidaemia.Development
Neurodevelopment.
Educational achievement.
Long-term disability in childhood.Other outcomes
Blood pressure.Adulthood
Body composition
BMI.
BMI greater than 25.
BMI greater than 30.
Weight.
Height.
Fat mass/ fat free mass.
Skin fold thickness measurements.Diabetes
Impaired glucose tolerance.
Type I diabetes.
Type II diabetes.
Insulin sensitivity.
Dyslipidaemia.Development
Educational achievement.Other outcomes
Blood pressure.
Core maternal and perinatal outcomes
CORE MATERNAL AND PERINATAL OUTCOMES (extracted from Devane 2007)
This paper identifies a minimum set of outcome measures for evaluating models of maternity care from the perspective of key stakeholders
GROUP 1 (from top 48 outcomes, in order of priority)
· Maternal death (death of a woman while pregnant or within 42 days of termination of pregnancy)
· Mode of birth (e.g. spontaneous vaginal, forceps, vaginal breech, caesarean section, vacuum extraction)
· Neonatal death (death before the age of 28 completed days following live birth)
· Stillbirth (a fetal death in late pregnancy)
· Type of labour onset (manner in which labour started i.e. induced, spontaneous, planned caesarean section
· Neonatal admission to special care and/or intensive care unit
· Birth injury to infant
· Ruptured uterus
· Postpartum haemorrhage (excess blood loss from the birth canal following childbirth)
· Mother requires admission to intensive care
· Maternal postnatal readmission to hospital
· Method of infant feeding
· Vaginal birth after previous caesarean section (VBAC)
· Gestational age at birth
· Postnatal depression
· Neonatal resuscitation required
· Normal (i.e. physiological) birth without intervention (vaginal birth without induction, episiotomy, or epidural)
· Oxytocin augmentation of labour
· Anal sphincter damage
· Hypoxic ischaemic encephalopathy (a condition of injury to the brain)
· Hypertensive disorders of pregnancy (including intrapartum)
· Puerperal psychosis (a mood disorder often accompanied by features such as loss of contact with reality, hallucinations, severe thought disturbance, and abnormal behaviour)
· Maternal faecal incontinence
· Birth asphyxia (occurs when a baby does not receive enough oxygen before, during or just after birth)
· Breastfeeding at discharge
· Neonatal readmission to hospital
· Apgar score at 5 min
· Breastfeeding at 3 months
· Maternal satisfaction (postnatal)
· Infant birthweight
· Neonatal fitting/seizures
· Infant requiring intubation
· Congenital anomaly (chromosomal and/or genetic and/or structural)
· Use of pharmacological analgesia/anaesthesia (e.g. Entonox, epidural, pethidine)
· Maternal satisfaction (antenatal)
· Postnatal hypertensive disorders of pregnancy
· Maternal satisfaction (intrapartum)
· Caesarean wound infection
· Pulmonary embolism
· Intrauterine growth restriction (commonly used when the birthweight is at or below the 10th percentile for gestational age and sex)
· Preterm labour (onset of labour prior to 37 completed weeks of pregnancy
· Meconium aspiration
· Intrapartum haemorrhage (excessive blood loss from the birth canal during labour)
· Neonatal infection
· Shoulder dystocia
GROUP 2 (other outcomes in order of priority)
· Maternal cerebral infarction
· Deep vein thrombosis
· Overall obstetric intervention score (list of interventions to indicate overall degree of invasive procedures)
· Fetal and/or neonatal haemorrhage
· Breastfeeding at 6 weeks
· Episiotomy
· Infant respiratory distress syndrome
· Inverted uterus
· Transfer/referral to medical-led care during labour
· Urinary incontinence (postnatal)
· Cord prolapsed
· Maternal preferences for future care
· Fetal acidosis
· Prolonged rupture of membranes
· Transfer/referral to medical-led care during pregnancy
· Need for blood transfusion
· Retained products of conception
· Rhesus isoimmunisation
· Manual removal of placenta
· Amniotomy
· Intact perineum
· Maternal attitudes toward routines and practices within model of care
· Time from decision to birth by emergency caesarean section
· Postmaturity (usually refers to any baby born after 42 weeks gestation)
· Breastfeeding at 6 months
· Retained placenta
· Length of infant hospital stay
· Longterm infant/child neurodevelopmental outcome
· Intrauterine hypoxia (lack of oxygen to the fetus)
· Perineal and vaginal tears
· Fetal distress
· Infant feeding problems
· Method of fetal heart rate monitoring
· Maternal perception of midwifery support during labour
· Length of second stage of labour
Devane D, Begley CM, Clarke M, Horey D, OBoyle C. Evaluating maternity care: a core set of outcome measures. Birth 2007;34(2):164-72