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 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 ASD02 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 ASD02 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 ASD02 for which the time elapsed between referral date and care contact date is between 91 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 ASD02 for which the time elapsed between referral date and care contact date is between 91 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 ASD02 for which the time elapsed between referral date and care contact date is more than 182 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 ASD02 for which the time elapsed between referral date and care contact date is more than 182 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

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.

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.

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 diagnosis records.

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 ASD09 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 ASD09 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 ASD09 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 ASD09 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