Comparing Interventions for Indoor Air -Related Functional Symptoms

Indoor air -related respiratory and other multiple organ symptoms are common in work environments in Finland. Symptoms effect on well-being and quality of life and may lead to impaired social and cognitive functioning and decreased work ability. All indoor air -related conditions are not explained by underlying physical factors and remain medically unexplained. Functional disorders are conditions where patients complain of multiple medically unexplained physical symptoms or physical problems don´t correlate with symptom severity. Indoor air -related symptoms and functional disorders are strongly associated to each other but there are no well-established diagnostic criteria for the condition . So far, there is no available treatment program to the indoor air -related symptoms to offer in primary or occupational health care services in Finland.

In randomized controlled trials, cognitive behavioral treatment has shown to be effective for patients suffering from functional disorders. In addition, a relaxation technique entitled as applied relaxation (Tuomisto & al, 1996) have shown to been shown to been effective to treat different kind of functional problems.

There are no published trials on treatment for individuals of indoor air related symptomatology. The present study is designed as a pragmatic trial to investigate the effect of three different treatment programs as compared to treatment as usual (TAU) for indoor air- related problems in order to improve the (1) work capacity and (2) well-being. A secondary aim of the study is to identify psychological factors affecting the patients' response to the treatment.

The patients are recruited from occupational health care services to establish and to evaluate the efficacy and usability of the treatment procedures. Participants will first undergo baseline assessment including medical examination of the respiratory symptoms. Then they are randomized to one of the study groups: TAU or one of the intervention groups. All study patients receive TAU at occupational health care services for their medical problems during the study. Patients randomized to the study groups receive also the intervention with TAU.

Inclusion criteria

• Self-assessed work ability not more than 7 (on a scale 0-10, compared to lifetime best) (removed, see below)
• Employed minimum three (3) or more years
• Symptoms related to work environment indoor air (non-industrial workplaces)
• Respiratory symptoms related to indoor air
• And symptoms involve more than one other organ system
• Symptoms onset maximum three years before the study
• Symptoms are recurrent
• Symptoms appear more than one (1) environment or continue after repairs environmental exposure(s)
• No single widely acceptable test of organ system function can explain the symptoms (symptoms are medically unexplained)
• Minimum of one sick leave due to indoor air symptoms during the preceding half year
• Fluent Finnish (write/read/speak) (due the interventions)

Exclusion criteria

• six (6) months or more sick leave sick leaves due to indoor air symptoms during the preceding two years and currently unable to work
• Planned changes in the work (for example retirement, study free period, pregnancy etc.) during the study
• An acute, untreated medical disorder or illnesses:

• Somatic disease that explains the symptoms
• An acute, untreated mental disorder (depression, bipolar disorder, psychotic disorders, obsessive-compulsive disorder, eating disorders, personality disorders)
• Abuse of narcotics or alcohol or (non-prescribed) medicine
• Developmental disorders
• Psychotherapy (current or has ended preceding two years)
• No inform consent
• Other: Patient refusal; not actively participating working life (retired or unemployed)

Based on a steering group´s advice and agreement (10.10.2014), inclusion criteria (Self-assessed work ability not more than 7, on a scale 0-10, compared to lifetime best) was removed. Recruitment continues without this question as an inclusion criteria.