Choosing a Sleep Study

An overnight sleep study at a sleep centre has always been the standard diagnostic test for detecting obstructive sleep apnea (OSA) and remains the 'gold standard' in diagnosis . Recent advances have made home sleep testing another option for people who are at risk for OSA.

SleepMed is able to provide both services, catered for the individual patient to give the best possible outcome. Follow our simple flow chart in our referral protocol to assist you in making a decision. The table below is a summary of the main advantages and disadvantages of the 2 options.

Methodology Standardised Non-standardised. Types 2, 3 and 4 devices vary in sophistication and data collection
Data collection Maximal – includes EEG, EOG, EMG, EFT, ECG, respiratory effort, airflow changes, oxygen Sats, snoring, body position and leg movements
At SleepMed, we use a Type 2 device which is the one most resembling a lab-based PSG. EEG, EOG, EMG, ECG, respiratory effort, airflow, oxygen Sats, body position +/- leg movements are also monitored.
Technician Overnight technician attendance Not supervised
Data credibility More credible
  • technician is available during the night to ensure quality of data collected is acceptable
  • less data loss
Less credible
  • patient may operate equipment incorrectly
  • higher data loss. Without professional supervision, electrodes can fall off, causing loss of or less accurate signals.
Ability to detect sleep disorders Able to detect all sleep disorders. Mostly used for detecting obstructive sleep apnoea and helpful for a handful of others
Portability study must be conducted in a sleep lab. may be conducted in patient’s home.
Contraindications None Contraindications include (see guidelines):
  • suspected disorders other than sleep apnea
  • co-morbid conditions

Diagnostic Limits

A Clinic based sleep study detects many other sleep disorders in addition to OSA. These include central sleep apnea, restless legs syndrome and parasomnias. They are effective if you have multiple medical problems or other suspected sleep disorders. A standard home sleep test detects OSA best. It does not record the signals needed to detect other sleep disorders accurately. Having particular medical problem or other suspected sleep disorders may affect the results of a home sleep test. This includes suspected hypoventilation (from morbid obesity, co-existing severe respiratory problems) or central sleep apnoea (eg heart failure or neurological conditions).

Age Limits

Home sleep tests may be inadequate for older adults who are likely to have other medical problems or sleep disorders that affect sleep. Validation research for this group has not been done.

Information Recorded

The study gathers signals about physiological parameters with each parameteron its own “channel.” Lab based studies record at least 12 channels. The system used by SleepMed Australia gathers at least 10 channels of information. In a clinic based study, the signal fidelity can be checked in real time and if a lead does not register, falls of or there are other technical issues, they are attended by the technician. With portable studies, this is not possible. However in only a minority of cases will there be insufficient data to necessitate re-testing.

Therapy Evaluation

The standard treatment for OSA is CPAP. In order to maximise therapy and ensure proper control or for troubles with the device, a CPAP-titration study may be required. A sleep technologist “titrates” the air pressure, raising or lowering it to reach an ideal setting. A lab-based sleep study is ideal for this. If a home sleep test detects that you have OSA, then you may be able to begin treatment at home with autotitrating CPAP (APAP). An APAP unit has an automatic, self-adjusting mode that raises or lowers the air pressure as needed.

Availability & Costs.

At SleepMed, we aim to cater for all sleep disorders and for all our patients’ wishes and circumstances. Whilst the clinic based studies are more labour intensive and costly to run, if you have private health cover, it may end up actually cheaper than a home study. Some insurers require a dedicated clinic study before paying towards the costs of your CPAP. Please call us on 1300 484 707 and we can assist you or your patients in which test best suits them.