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Publication, Part of

Autism Waiting Time Statistics - Quarter 1 2019-20 to Quarter 2 2020-21 and Quarter 3 (October to December) 2020-21

Experimental statistics, Official statistics in development

Update to methodology in measures ASD01g, ASD01i and their corresponding percentages

An issue in the methodology originally published was identified post-publication in the referral to care contact component of the publication. This related to the cut off date used for a referral to have been discharged from service without a diagnosis or care contact or for a referral to still be waiting for a diagnosis or care contact.

The cut off date used originally for these measures was the end date of each reporting quarter, it has now been changed to the end of the final full quarter of performance data available.

An updated data file is provided below, suffixed with v2.

29 June 2021 09:00 AM

Construction

Forward model

Determination of the denominator

The denominator for the measures calculated in the forward model is patients with a new referral for suspected autism in a reporting period (in this case the reporting period is a quarter) for which a care contact date is recorded by the latest available submission at the time of publication.

A referral record is in-scope for these statistics if:

  1. The coded reason for referral is ’25’ (suspected autism)

This is irrespective of whether this referral ends in a diagnosis of autism. 

Step-by-step construction and measures

Step 1: Get all records with suspected autism (MHSDS Reason for referral = '25' - suspected autism) as the referral reason within the reporting period from tables MHS101 and MHS103

Step 2: Join these referral records to the master patient index (MHS001) to allow demographic information to be gained for each patient

Step 3: Link the combined referral and demographic records to the first attended care contact date recorded for each referral, ensuring that this contact is the earliest associated with each referral. Types of contact considered for this analysis are face to face or telemedicine web camera.

Step 4: Construct measures based on the length of time elapsed (in days) between initial referral and care contact received, as follows:

ASD01 - Number of new referrals for suspected autism starting during the reporting period

Count of all unique referrals between the reporting period start date and reporting period end date

ASD02 - Number of new referrals for suspected autism starting in the reporting period having a first appointment recorded

Count of all unique referrals between the reporting period start date and reporting period end date where the care contact date is not null

ASD03 - Number of new referrals for suspected autism in the reporting period receiving a first appointment in 13 weeks or less

Count of all unique referrals from ASD01 for which the time elapsed between referral date and care contact date is equal to or less than 91 days (13 weeks)

ASD04 - Proportion of new referrals for suspected autism in the reporting period receiving a first appointment in 13 weeks or less

Proportion of the unique referrals from ASD01 for which the time elapsed between referral date and care contact date is less than or equal to 91 days (13 weeks), displayed as a percentage

ASD05 - Number of new referrals for suspected autism in the reporting period receiving a first appointment between 13 weeks and 26 weeks

Count of all unique referrals from ASD01 for which the time elapsed between referral date and care contact date is between 92 days and 182 days (13 weeks - 26 weeks)

ASD06 - Proportion of new referrals for suspected autism in the reporting period receiving a first appointment between 13 weeks and 26 weeks

Proportion of the unique referrals from ASD01 for which the time elapsed between referral date and care contact date is between 92 days and 182 days (13 weeks - 26 weeks), displayed as a percentage

ASD07 - Number of new referrals for suspected autism in the reporting period receiving a first appointment at more than 26 weeks

Count of all unique referrals from ASD01 for which the time elapsed between referral date and care contact date is more than or equal to 183 days (26 weeks)

ASD08 - Proportion of new referrals for suspected autism in the reporting period receiving a first appointment at more than 26 weeks

Proportion of the unique referrals from ASD01 for which the time elapsed between referral date and care contact date is more than or equal to 183 days (26 weeks), displayed as a percentage

ASD09 - Number of new referrals for suspected autism in the reporting period not having a first appointment recorded

Number of unique referrals from ASD01 for which the contact date is null

Changes in the construction of the forward model since the November 2019 release

In the previous release of the forward model statistics the volumes of referrals are higher due to the way the referral cohort was put together.

The previous analysis was undertaken before migration of the Mental Health Services Dataset to the Data Access Environment, at which point only data up to 31 March 2019 was available.

For each quarter the analysis previously took all referrals with a referral date within the quarter, but the record could have been submitted on any date up to 31 March 2019.

This new version of the forward model is going to be published as a quarterly series in a rolling year model. This is a more robust method and will allow comparison of referral volumes between reporting periods. The changes to the methodology are as follows:

  1. For each quarter, we now take all referrals for suspected autism that have a referral date within the quarter that have also been submitted within the quarter.
  2. The waiting time measures are now calculated from only the group of patients who have a first care contact recorded. An additional column showing this denominator is now included in the published data for transparency. This has now changed and is detailed further down in the newest changes update section.

Changes in the construction of the forward model since the August 2020 release

In the August 2020 release, the time elapsed between initial referral and first care contact was only broken down into less than or equal to 13 weeks, or greater than 13 weeks. Through development and collaboration with stakeholders we have taken the decision to remove the average (mean) waiting time from initial referral to first care contact and replace this with a more granular "time elapsed" breakdown, which is now presented as follows:

Number (and proportion) of new referrals for suspected autism in the reporting period receiving a first appointment in 13 weeks or less

Number (and proportion) of new referrals for suspected autism in the reporting period receiving a first appointment between 13 weeks and 26 weeks

Number (and proportion) of new referrals for suspected autism in the reporting period receiving a first appointment at more than 26 weeks

The average (mean) waiting time was removed from the forward model statistics because it was not comparable across quarters. This was due to the differing lengths of time elapsed for which the average waiting time could be measured.

Changes in the construction of the forward model since the September 2020 release

The waiting time measures are now calculated from the whole group of referrals for suspected autism. In the August and September editions of this publication, they were calculated only from the group of referrals for which there was a care contact recorded. The additional column showing the number of referrals for which a care contact has been recorded is left in for reference.

In addition to the existing demographics and provider breakdowns, Clinical Commissioning Group (CCG) and Sustainability and Transformation Partnership (STP) breakdowns have now been added.

As these statistics are under continuous development, it is likely that changes will be implemented throughout this development. With the aim of transparency and development of high quality reliable statistics, all changes made to the methodology will be documented in full here.

Additional breakdowns (measures) added to the forward model since the March 2021 release

The denominator for the additional measures calculated in the forward model is patients with a new referral for suspected autism in a reporting period (ASD01) and additional measures (ASD01a to ASD01j) are constructed for these referrals based on whether a diagnosis or a care contact date or a discharge date is recorded by the latest available submission at the time of publication.

Step-by-step construction and measures

Step 1: For all referrals with suspected autism within the reporting period, link to primary or secondary diagnosis tables (tables MHS604 and MHS605, respectively) to get diagnosis details recorded.

Step 2: Group the referrals based on whether they have an autism diagnosis or other diagnosis recorded.

Step 3: For referrals without a diagnosis recorded check whether an attended care contact is recorded.

Step 4: For rest of the referrals with no diagnosis or care contact recorded link to master patient index (MHS001) to get discharge information recorded.

Step 5: Construct additional measures as follows:

ASD01a - Number of new referrals for suspected autism in the reporting period having an autism diagnosis recorded

Count of all unique referrals from ASD01 for which an autism diagnosis is recorded

ASD01b - Proportion of new referrals for suspected autism in the reporting period having an autism diagnosis recorded

Proportion of all unique referrals from ASD01 for which an autism diagnosis is recorded, displayed as a percentage

ASD01c - Number of new referrals for suspected autism in the reporting period having a diagnosis recorded but not for autism

Count of all unique referrals from ASD01 for which a diagnosis other than autism is recorded

ASD01d - Proportion of new referrals for suspected autism in the reporting period having a diagnosis recorded but not for autism

Proportion of all unique referrals from ASD01 for which a diagnosis other than autism is recorded, displayed as a percentage

ASD01e - Number of new referrals for suspected autism in the reporting period waiting for a diagnosis but had a care contact recorded

Count of all unique referrals from ASD01 do not have a diagnosis recorded but have a care contact recorded (care contact date is not null)

ASD01f - Proportion of new referrals for suspected autism in the reporting period waiting for a diagnosis but had a care contact recorded

Proportion of all unique referrals from ASD01 do not have a diagnosis recorded but have a care contact recorded (care contact date is not null), displayed as a percentage

ASD01g - Number of new referrals for suspected autism in the reporting period recorded as discharged from service without a diagnosis or care contact

Count of all unique referrals from ASD01 without a diagnosis or care contact recorded but have a discharge date populated

ASD01h - Proportion of new referrals for suspected autism in the reporting period recorded as discharged from service without a diagnosis or care contact

Proportion of all unique referrals from ASD01 without a diagnosis or care contact recorded but have a discharge date populated, displayed as a percentage

ASD01i - Number of new referrals for suspected autism in the reporting period still waiting for a diagnosis or care contact

Count of all unique referrals from ASD01 without a diagnosis or care contact and have discharge date as null or discharge date after the cut-off end date (based on the latest available submission at the time of publication)

ASD01j - Proportion of new referrals for suspected autism in the reporting period still waiting for a diagnosis or care contact

Proportion of all unique referrals from ASD01 without a diagnosis or care contact and have a discharge date as null or discharge date after the cut-off end date (based on the latest available submission at the time of publication), displayed as a percentage


Reverse model

Determination of the denominator

The denominator for the measures calculated in the reverse model is patients with a new diagnosis for autism in a reporting period.

A diagnosis record is in-scope for these statistics if:

  1. The coded diagnosis record in MHSDS tables MHS604PrimDiag and MHS605SecDiag falls within the specified list of SNOMED or ICD-10 codes for autism spectrum disorders, described in full in the completeness section of the data quality page here.

This is irrespective of the reason for referral leading to these diagnoses being recorded.

Step-by-step construction and measures

Step 1: Get all records with an autism spectrum disorder diagnosis recorded in the primary or secondary diagnosis tables (tables MHS604 and MHS605, respectively)

Step 2: Link all the diagnosis records to the associated referral record in table MHS101

Step 3: Ensure that each diagnosis record is in fact the earliest diagnosis for autism for each referral, taking one diagnosis record per referral where there are multiple diagnosis records per referral

Step 4: Link all records to the master patient index (MHS001) to gain demographic records for each patient and link to MHS103 to get the breakdown by reason for referral

Step 5: Construct measures based on the length of time elapsed between the initial referral and the diagnosis associated with that referral, as follows:

ASD10 - Number of new diagnoses of autism recorded during the reporting period

Count of all unique diagnoses between the quarter start date and quarter end date

ASD11 - Number of new diagnoses of autism recorded during the reporting period with 13 weeks or less between referral and diagnosis

Count of all unique referrals from ASD10 for which the time elapsed between referral date and diagnosis date is less than or equal to 91 days (13 weeks)

ASD12 - Proportion of new diagnoses of autism recorded during the reporting period with 13 weeks or less between referral and diagnosis

Proportion of all unique referrals from ASD10 for which the time elapsed between referral date and diagnosis date is equal to or less than 91 days (13 weeks), displayed as a percentage

ASD13 - Number of new diagnoses of autism recorded during the reporting period with more than 13 weeks between referral and diagnosis

Count of all unique referrals from ASD10 for which the time elapsed between referral date and diagnosis date is more than 91 days (13 weeks)

ASD14 - Proportion of new diagnoses of autism recorded during the reporting period with more than 13 weeks between referral and diagnosis

Proportion of all unique referrals from ASD10 for which the time elapsed between referral date and diagnosis date is more than 91 days (13 weeks), displayed as a percentage

ASD15 – Average length of time between referral and diagnosis

The average (mean) of all the times elapsed in days for each referral to diagnosis record


Last edited: 6 July 2021 9:39 am