Introduction PCUs in Thailand are able to provide some occupational health services activities. Occupational diseases (OD) are difficult to diagnose for several reasons:

• the similarities in the clinical presentation and pathophysiology between occupational and non–occupational exposures;

• the long latency period between exposure and symptom onset;

• the multifactorial aetiology of many chronic diseases; and

• no data of work–related conditions. If PCUs could provide OD diagnosis, patients with suspected OD will be benefit from referral to an occupational medicine specialist for a more detailed assessment, under–report of OD and risk from work will be managed. This study aimed to develop OD recognising and record system to strengthen OHS data system.

Methods The screening questions were developed to identify potential occupational causes of symptoms. Meanwhile, Bureau of Occupational and Environmental Diseases has collaborated with the Health Data Centre (HDC) of the Ministry of Public Health to add the 14 common OD in the data system. PCUs were recommended to use such screening questions, provide OD diagnosis and record in the data system.

Results Screening questions include what kind of job patients have; whether their symptoms are worse at work; whether they are or have been exposed to dust, fumes, chemicals, or loud noise; whether their colleagues have similar symptoms and whether they think their health problems may be related to their works. Currently, 2031 (20.78%) of total PCUs could use such questions to identify OD and add external cause ICD-10 code (Y96) to the record system. All data link to HDC therefore the national and local agencies could access OD statistics through HDC.

Conclusion Such screening questions are very useful and important for PCUs, especially when the diagnosis or aetiology is in doubt. Occupational health services among PCUs should be strengthened to obtain the quality data.