Sickle cell and thalassaemia screening standards valid for data collected from 1 April 2018
Updated 24 July 2023
Applies to England
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SCT-S01: coverage: antenatal screening
Description
The proportion of pregnant women eligible for antenatal sickle cell and thalassaemia (SCT) screening for whom a screening result is available at the day of report.
Rationale
To provide assurance that screening is offered to all eligible women, and each woman accepting screening has a screening result.
Coverage is a measure of the delivery of screening to an eligible population.
Low coverage might indicate that:
- not all eligible women were offered screening
- those offered screening are not accepting the test
- those accepting the test are not tested
Definition
Numerator: tested women is the total number of eligible women for whom a screening result is available for sickle cell and thalassaemia at the day of report, including known at risk couples referred directly for prenatal diagnosis (PND). Repeat testing must not delay referral.
Denominator: eligible women is the total number of pregnant women booked for antenatal care or presenting in labour without previously having booked for antenatal care in the reporting period excluding women who:
- miscarry between bookingand testing
- opt for termination between booking and testing
- transfer out between booking and testing (do not have a result)
- transfer in who have a result from a screening test performed elsewhere in the NHS in this pregnancy
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Performance thresholds
Acceptable level: greater than or equal to 95.0%
Achievable level: greater than or equal to 99.0%
Caveats
Requires matched cohort data and follow-up of any missed women
Data collection and reporting
Data source: maternity service and screening laboratory
Responsible for data quality and completeness: maternity service
Responsible for submission: maternity service
Reported by: maternity service
Published by: maternity service
This standard is also the key performance indicator ST1.
Reporting period
Quarterly: data to be collated between 2 and 3 months after each quarter end.
Deadlines: 30 September (Q1), 31 December (Q2), 31 March (Q3), 30 June (Q4).
Review dates
Date standard introduced: April 2012
Date standard last updated: April 2019
SCT-S02: test: timeliness of antenatal screening
Description
The proportion of pregnant women having antenatal sickle cell and thalassaemia screening for whom a screening result is available before or at 10 weeks plus 0 days gestation.
Rationale
To maximise the opportunity of informed choice by identifying carrier and affected women before or at 10 weeks plus 0 days of gestation.
Definition
Numerator: women where test result is available less than or equal to 10 weeks plus 0 days gestation is the total number of pregnant women for whom a screening sample was received in the laboratory and for whom an antenatal SCT screening result was available (though not necessarily communicated to the woman) before or at 10 weeks plus 0 days gestation (before or at 70 days).
Denominator: women for whom screening sample received at laboratory is the total number of pregnant women for whom an antenatal SCT screening sample was received at the laboratory during the reporting period excluding full blood count samples where the request is other than antenatal screening.
Calculation of gestational age may be based on last menstrual period or ultrasound scan.
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Performance thresholds
Acceptable level: greater than or equal to 50.0%
Achievable level: greater than or equal to 75.0%
Caveats
Does not need to be matched cohort.
Data collection and reporting
Data source: maternity service and screening laboratory
Responsible for data quality and completeness: maternity service
Responsible for submission: maternity service
Reported by: maternity service
Published by: maternity service
This is also the key performance indicator ST2.
Reporting period
Quarterly: data to be collated between 2 and 3 months after each quarter end.
Deadlines: 30 September (Q1), 31 December (Q2), 31 March (Q3), 30 June (Q4).
Review dates
Date standard introduced: April 2012
Date standard last updated: April 2019
SCT-S03: test: completion of family origin questionnaire (FOQ)
Description
The proportion of antenatal SCT samples submitted to the laboratory accompanied by a completed family origin questionnaire.
Rationale
To interpret screening results in high prevalence areas and to identify women at higher risk to be offered further testing in low prevalence areas.
Definition
Numerator: number of antenatal screening samples received by the laboratory with completed FOQ.
A completed FOQ must use the national template (paper or electronic format) and must include:
- at least 1 box for the mother or options for ‘declined to answer’ or ‘don’t know’ selected
- at least 1 box for the father or options for ‘declined to answer’ or ‘don’t know’ selected
- gestational age or gestational age ‘not known’ recorded
Denominator: number of antenatal screening samples for SCT testing received by the laboratory in the reporting period.
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Performance thresholds
Acceptable level: greater than or equal to 95.0%
Achievable level: greater than or equal to 99.0%
Caveats
This data does not need to be matched cohort.
Laboratories that serve more than one maternity service must report by each maternity service.
Data collection and reporting
Data source: maternity service and screening laboratory
Responsible for data quality and completeness: maternity service and screening laboratory
Responsible for submission: maternity service
Reported by: maternity service
Published by: maternity service
This standard is also the key performance indicator ST3.
Reporting period
Quarterly: data to be collated between 2 and 3 months after each quarter end.
Deadlines: 30 September (Q1), 31 December (Q2), 31 March (Q3), 30 June (Q4).
Review dates
Date standard introduced: April 2012
Date standard last updated: April 2019
SCT-S04: test: turnaround time (antenatal screening)
Description
Proportion of antenatal results, interim reports and requests for repeat tests reported on or before 3 working days.
Rationale
To maximise the opportunity of informed choice through timely offer of screening to babies’ biological fathers or urgent requests for repeat samples.
Definition
Numerator: number of antenatal results, interim reports and requests for repeat tests reported on or before 3 working days of receipt of sample.
Denominator: number of antenatal samples received in the laboratory in the reporting period.
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Count receipt of sample (day 1) when the specimen is received in the reception in the first laboratory.
Performance thresholds
Acceptable level: greater than or equal to 90.0%
Achievable level: greater than or equal to 95.0%
Caveats
None.
Data collection and reporting
Data source: antenatal screening laboratory
Responsible for data quality and completeness: screening laboratory
Responsible for submission: screening laboratory
Reported by: screening laboratory
Published by: antenatal screening laboratory
Reporting period
Annually by 30 June
Review dates
Date standard introduced: April 2012
Date standard last updated: April 2019
SCT-S05: referral: timely offer of prenatal diagnosis (PND) to women at risk of having an infant with sickle cell disease or thalassaemia
Description
Proportion of women at increased risk of having a baby with sickle cell disease or thalassaemia offered PND before or at 12 weeks plus 0 days gestation. This standard is reported in 2 parts: S05a (women at risk), and S05b (couples at risk).
Rationale
To maximise informed choice by the early offer of PND.
S05a: women at risk
Numerator: women at risk of having an infant with SCT offered PND before or at 12 weeks plus 0 days gestation.
Denominator: women at risk of having an infant with SCT. This is the total number of women in the reporting period who are carriers of, or affected by, a clinically significant haemoglobin variant where the haemoglobinopathy status of the baby’s biological father is unknown, or pregnancies by donor egg or sperm where the haemoglobinopathy status of the donor is unknown.
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Clinically significant haemoglobin variants where the baby’s biological father’s status or donor’s status is unknown are:
- Hb S
- Hb C
- Hb DPunjab
- Hb E
- Hb OArab
- Hb Lepore
- β thalassaemia
- δβ thalassaemia
- α0 thalassaemia (- -/aa)
- Hereditary Persistence of Fetal Haemoglobin (HPFH)
- other haemoglobin variants detected which may result in a serious haemoglobin disorder
- any compound heterozygote or homozygous state of these conditions
S05b: couples at risk
Numerator: couples at risk of having an infant with SCT offered PND before or at 12 weeks plus 0 days gestation.
Denominator: couples at risk of having an infant with SCT. This is the total number of couples in the reporting period with a 1 in 4 chance or higher (mother and father results known) of the fetus being affected by a serious haemoglobin disorder (SCT).
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Results that mean there is a 1 in 4 chance or higher of the fetus being affected are biological mothers who are carriers for, or affected by:
- Hb S and baby’s biological father is a carrier or affected by Hb S, β thalassaemia, Hb DPunjab, Hb C, or Hb OArab
- β thalassaemia and baby’s biological father is a carrier or affected by Hb S, β thalassaemia, δβ thalassaemia, Hb Lepore, or Hb E
- δβ thalassaemia and baby’s biological father is a carrier or affected by β thalassaemia or Hb Lepore
- Hb Lepore and baby’s biological father is a carrier or affected by β thalassaemia, δβ thalassaemia, or Hb Lepore
- Hb DPunjab and baby’s biological father is a carrier or affected by Hb S
- Hb C and baby’s biological father is a carrier or affected by Hb S
- Hb E and baby’s biological father is a carrier or affected by β thalassaemia
- Hb OArab and baby’s biological father is a carrier or affected by Hb S
Other results that mean there is a 1 in 4 chance or higher of the fetus being affected are if:
- both of the baby’s biological parents are at high risk of α0 thalassaemia
- parents have any other haemoglobin variants detected which may result in a serious haemoglobin disorder
Calculation of gestational age may be based on last menstrual period or ultrasound scan.
Performance thresholds
Acceptable level: to be set
Achievable level: to be set
Caveats
None.
Data collection and reporting
Data source: maternity service and specialist SCT counselling services
Responsible for data quality and completeness: maternity service and specialist SCT counselling services
Responsible for submission: maternity service
Reported by: maternity service
Published by: maternity service
This standard is also the key performance indicator ST4.
Reporting period
Quarterly data to be collated between 2 and 3 months after each quarter end.
Deadlines: 30 September (Q1), 31 December (Q2), 31 March (Q3), 30 June (Q4).
Review dates
Date standard introduced: April 2017
Date standard last updated: April 2019
SCT-S06: diagnosis or intervention: timeliness of prenatal diagnosis (PND)
Description
Proportion of PND tests performed before or at 12 weeks plus 6 days gestation.
Rationale
To maximise informed choice by the early offer of PND test.
Advanced gestational age may limit reproductive choices.
Definition
Numerator: number of women who have PND before or at 12 weeks plus 6 days gestation.
Denominator: number of women who have PND in the reporting period.
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Performance thresholds
Acceptable level: greater than or equal to 50.0%
Achievable level: greater than or equal to 75.0%
Caveats
None
Data collection and reporting
Data source: PND laboratory
Responsible for data quality and completeness: PND laboratory and maternity service
Responsible for submission: National Congenital Anomaly and Rare Disease Registration Service (NCARDRS)
Reported by: maternity service
Published by: maternity service
Reporting period
Annually by 31 October
Review dates
Date standard introduced: April 2012
Date standard last updated: April 2019
SCT-S07: test: timely reporting of prenatal diagnosis (PND) results to parents
Description
Proportion of women receiving results before or at 5 working days from PND procedure.
Rationale
To maximise informed choice by providing information about living with and supporting a child with sickle cell disease or thalassaemia and termination of pregnancy as early as possible.
Definition
Numerator: number of women who receive their result before or at 5 working days from PND test.
Denominator: number of women who have PND in the reporting period.
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Performance thresholds
Acceptable level: greater than or equal to 70.0%
Achievable level: greater than or equal to 90.0%
Caveats
None
Data collection and reporting
Data source: maternity service and specialist SCT counselling services
Responsible for data quality and completeness: maternity service and specialist SCT counselling services
Responsible for submission: maternity service
Reported by: maternity service
Published by: maternity service
Reporting period
Annually by 30 June
Review dates
Date standard introduced: April 2012
Date standard last updated: April 2019
SCT-S08: test: reporting newborn screen positive results to parents
Description
Proportion of parents receiving newborn screen positive results before or at 28 days of age.
Rationale
To provide timely results to parents of screen positive infants in order to give support to parents and carers, emphasise the importance of early penicillin prophylaxis and to ensure prompt referral into treatment.
Definition
Numerator: number of newborn infants with screen positive results for whom parents receive results before or at 28 days of age.
Denominator: number of newborn infants born within the reporting period with screen positive results.
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Specified conditions to be detected in newborn screening are: HbSS, HbSC, HbS/β thalassaemia (S/β+, S/β°, HbS/δβ, HbS/γδβ, S/Lepore), HbS/DPunjab, HbS/E, HbS/OArab, HbS/HPFH, Hb S with any other variant and no Hb A, and other clinically significant haemoglobinopathies likely to be detected as by-products of newborn screening including β thalassaemia major, Hb E/β thalassaemia, and β thalassaemia intermedia.
Carrier results need to be followed up but are excluded from this standard.
Performance thresholds
Acceptable level: greater than or equal to 90.0%
Achievable level: greater than or equal to 95.0%
Caveats
Detection of thalassaemia is not part of the programme but we expect beta thalassaemia major to be detected as a by-product and the same standards for communicating results to parents and enrolment into care apply.
Data collection and reporting
Data source: haemoglobinopathy centre
Responsible for data quality and completeness: haemoglobinopathy centre
Responsible for submission: NCARDRS and or newborn screening outcomes system
Reported by: haemoglobinopathy centre
Published by: haemoglobinopathy centre
Reporting period
Annually by 31 October.
Review dates
Date standard introduced: April 2012
Date standard last updated: April 2019
SCT-S09: intervention or treatment: timely follow-up, diagnosis and treatment of newborn infants with a positive screening result
Description
Proportion of newborn infants with a positive screening result who are seen at a paediatric clinic or discharged for insignificant results before or at 90 days of age.
Rationale
To optimise individual health outcomes, penicillin prophylaxis should start by 90 days of age in children with sickle cell disease. Parents of infants with insignificant results must be reassured as early as possible.
Definition
Numerator: number of newborn infants with clinically significant results who are seen by a paediatrician before or at 90 days of age and those with insignificant results who are discharged before or at 90 days of age.
Denominator: number of newborn infants with screen positive result born within the reporting period excluding infants who:
- are born outside England
- die or move abroad before 90 days of age
We calculate performance by dividing numerator by denominator and multiplying by 100 to give a percentage.
Specified conditions to be detected in newborn screening are: HbSS, HbSC, HbS/β thalassaemia (S/β+, S/β°, HbS/dβ, HbS/γdβ, S/Lepore), HbS/DPunjab, HbS/E, HbS/OArab, HbS/HPFH, Hb S with any other variant and no Hb A, and other clinically significant haemoglobinopathies likely to be detected as by-products of newborn screening including β thalassaemia major, Hb E/β thalassaemia and β thalassaemia intermedia.
Performance thresholds
Acceptable: greater than or equal to 90.0%
Achievable: greater than or equal to 95.0%
Caveats
None
Data collection and reporting
Data source: haemoglobinopathy centre
Responsible for data quality and completeness: haemoglobinopathy centre
Responsible for submission: NCARDRS and or newborn screening outcomes system
Reported by: haemoglobinopathy centre
Published by: haemoglobinopathy centre
Reporting period
Annually by 31 October
Review dates
Date standard introduced: April 2012
Date standard last updated: April 2019