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Recording smoking status data in MSDS

We have produced some guidance on recording smoking status data in the Maternity Services Dataset (MSDS).

Aim

Smoking whilst pregnant is extremely dangerous as inhaling carbon monoxide, a harmful chemical present in cigarette smoke, reduces the amount of oxygen getting to the baby in the womb and increases the chance of miscarriage, stillbirth and sudden infant death. Therefore, it is important to monitor smoking rates at booking up until delivery so appropriate support can be provided to pregnant women and new mums. This guidance page explains how the smoking status of pregnant women should be recorded in the Maternity Services Dataset (MSDS).


Smoking status at time of booking

In order to derive the Smoking at Time of Booking metric from MSDS, a self-declared smoking status needs to be recorded within -/+ 3 days of the booking appointment date. This needs to be recorded using clinical codes in the MSD202 Care Activity (Pregnancy) table using the Coded Finding or Coded Observation field, ideally using the SNOMED codes listed below in Table 1. 

For this particular metric, a carbon monoxide (CO) reading is also required. This should be completed using the Coded Observation field (ObsCode), using the SNOMED code: 251900003 Expired carbon monoxide concentration (observable entity), as well as completion of the Observation Value (ObsValue) and UCUM unit of measurement (UCUMUnit) fields. The UCUM unit of measurement needs to be in parts-per-million (ppm or coppm). 


Smoking status at the 36-week appointment

In order to derive the Smoking at the 36-week appointment metric from MSDS (for the Saving Babies Lives programme), a self-declared smoking status needs to be recorded within -/+ 3 days of the 36-week appointment date. This needs to be recorded using clinical codes in the MSD202 Care Activity (Pregnancy) table using the Coded Finding or Coded Observation field, ideally using the SNOMED codes listed below in Table 1. 

For this particular metric, a carbon monoxide (CO) reading is also required. This should be completed using the Coded Observation field (ObsCode) with the SNOMED code: 251900003 Expired carbon monoxide concentration (observable entity), as well as completion of the Observation Value (ObsValue) and UCUM unit of measurement (UCUMUnit) fields. The UCUM unit of measurement needs to be in parts-per-million (ppm or coppm). 

To note, the Smoking at 36-week Appointment metric is yet to be developed for publication. Further information can be found in the SBLCBv3 Technical Glossary.


Smoking status at time of delivery

In order to derive the Smoking at Time of Delivery metric from MSDS, a self-declared smoking status needs to be recorded within -/+ 3 days of the labour onset date using a clinical code, such as SNOMED CT. This needs to be recorded in the MSD302 Care Activity (Labour and Delivery) table using the Coded Finding or Coded Observation field, ideally using the SNOMED CT codes listed below in Table 1. 


Clinical codes

For each of these smoking metrics, please use one of the following SNOMED codes and please select SNOMED CT in the Finding Scheme in Use (FindingScheme) or Observation Scheme in Use (ObsScheme) fields in the respective tables mentioned above: 

Table 1: Clinical codes for smoking status 

Group SNOMED CT code Description
Current smoker 77176002  Smoker (finding) 
Non-smoker  266919005  Never smoked tobacco (finding) 
  8517006  Ex-smoker (finding) 
  8392000  Non-smoker (finding)
  405746006  Current non-smoker but past smoking history unknown (finding) 

If no code is submitted, then the woman’s record will default to having an unknown smoking status for the period in question. 

Please ensure there is no conflicting information recorded in MSDS on the smoking status within the period in question, for example, smoker and non-smoker recorded within -/+ 3 days from the labour onset date. This conflicting information will result in assigning a smoking status of unknown, which is not helpful for analysis. 


Further information

For further information on how MSDS metrics are put together, please see the metadata for the monthly publication for the smoking at time of booking metrics. However, the Smoking at Time of Delivery metric has its own separate publication and metadata

Access the MSDS v2.0 Technical Output Specification for further information on the data items and tables submitted for MSDS.

 

Last edited: 16 January 2025 1:07 pm