Ratings of Treatment Studies for Autism

Child with autism riding a horse Our ratings are designed to tell you what scientific evidence has been published in peer-reviewed journals that supports or does not support the effectiveness of a particular intervention for use with people with autism spectrum disorders.

The rating for each intervention is based on the quality and the number of scientific research studies on that intervention.

The greater the number of high quality research studies which support the intervention, the higher the number of ticks.

The greater the number of high quality research studies which do not support the intervention, the higher the number of crosses.

Where there is limited or mixed evidence we show this with a question mark.

Where there is no evidence we show this with a zero.

When we have been been unable to identify any research studies on a given intervention, this does not prove that the intervention is ineffective. It simply shows that we have been unable to identify any relevant studies from a range of relevant databases and other sources

We are aware that this approach may not reflect the views of all our readers, but only in this way can we be sure that the findings we report are based on the most reliable, valid and unbiased data available at the current time. We may of course modify the rating for an intervention when new scientific data on that intervention are published.

Disclaimer

Please note that our ratings do not constitute a recommendation about whether or not an intervention is suitable for a particular individual with autism. Each individual with autism is different and what works for one individual may not work for another.

Quality rating

3 ticks. Very strong, positive evidence Very strong, positive evidence

2 or more Grade A studies or
1 Grade A study and 3 or more Grade B studies

The majority of these studies show significant positive effects

2 ticks. Strong, positive evidence Strong, positive evidence

2 or more Grade B studies

The majority of these studies show significant positive effects

1 tick. Limited positive evidence Limited, positive evidence

At least 1 Grade B study or
2 or more Grade C (cases series) studies,

The majority of these studies show significant positive effects.

Zero. Insufficient or mixed evidence Insufficient/Mixed evidence

Some Grade B/C studies but findings inconsistent or
Some Grade D studies or less than 2 Grade C studies only.

No evidence

We have been unable to identify any studies of this intervention being used to help people with autism spectrum disorders published in peer-reviewed journals

1 tick. Some negative evidence Some negative evidence

At least 1 Grade B study or
2 or more Grade C (cases series) studies case series studies showing no significant effects

2 crosses. Strong, negative evidence Strong negative evidence.

1 Grade A study or
2 or more Grade B studies

The majority of these studies show no significant effects.

3 crosses. Very strong, negative evidence Very strong negative evidence.

More than 1 Grade A study showing no significant positive effects or
3 or more Grade B studies showing no significant positive effects or
1 Grade A study plus more than 2 Grade B studies showing no significant effects.

Not graded ratings

Ungraded

We have provided some information about this intervention but we have not yet had the opportunity to rate the scientific evidence for its effectiveness.

Not Applicable

It is not possible to provide a rank for this intervention. This is usually because the intervention described, such as speech and language therapy, incorporates a wide range of other interventions, methods and techniques.

Hazard rating

Evidence of harmful effects.

Objective evidence indicating significant adverse/harmful effects.

What do the grades mean?