Prevalence and factors associated with medication compliance in Indian patients suffering from mental disorders

Introduction

Non-adherence in drug therapy for psychiatric disorders can cause increased morbidity, mortality and an enormous cost to the health-care system. ¹ Improving adherence has a far greater impact on the health of a population than any specific medical treatment. There have been only a few studies from Indian settings which have investigated compliance and the associated factors in mental disorders. This study examined the rates of medication, non-adherence, associated disease, illness, treatment and physician-related factors of compliance among patients with mental disorders.

Material and methods

This is a prospective cross-sectional study of self-reported adherence in patients with mental disorders attending the outpatient department of a super specialty hospital from January–June 2009, which evaluates non-adherence (3–10 doses skipped in a month) and adherence (0–3 doses skipped in a month). ² The inclusion criteria included patients aged >18 years of either gender who had been receiving treatment for six months and who were willing to give consent. We excluded those suffering from acute mania, acute psychotic episodes or severe depression with currently suicidal ideation and any organic causes for their behavioural disturbance and those suffering from organic brain syndromes or mental retardation.

Results

A total of 400 patients (59.7% men, 40.3% women, mean age of 32.1 ± 9.67) were enrolled and their demographic characteristics were compared (Table 1). The majority were suffering from schizophrenia (54.3%), bipolar affective disorder (BPAD; 31.8%) or depression (14%). About 153 (38.25%) reported non-adherence of whom 77 (50.32%) suffered from schizophrenia, 51 (33.33%) from BPAD and 25 (16.33%) from depression. Non-adherence among those with depression was 44.6%, followed by 40.2% among those with BPAD and 35.5% with schizophrenia. Medication adherence was significantly higher (41.3%) among the younger patients (18–27 years; P < 0.05, odds ratio [OR] 3.02).

The majority (93.75%) of patients had good social support (availability of family and friends in times of need). Those with parental support (91.2%) had a significantly better compliance (P < 0.05, OR 4.67). A lack of knowledge and awareness about the course of illness and treatment was the most common reason for poor drug compliance. Those with mild illness (67.25%) had a significantly better adherence (Table 2). Polypharmacy (≥3 medicines) was observed in 47%. There was no significant difference between the average number of medicines prescribed (2.50 ± 0.94 [range 1–6], mean number of pills/day was 5.07 ± 2.53 [range 1–15]) and 94.51% of the medicines prescribed were dispensed from the hospital pharmacy. Mild to moderate sedation and tiredness was experienced by 69% but non-adherent patients complained of severe sedation (P < 0.05; OR 4.18).

Discussion

There was a high overall prevalence of non-adherence among those with depression, schizophrenia or BPAD. The mean prevalence of non-adherence in schizophrenia reported in the published literature is around 40–50%, ^1,2 which is slightly higher than our study – BPAD 10–60% (median 40%) ³ compared with 39.7–52.7% with a mean of 46.5% in depression. ⁴

Contrary to our findings, where the younger age group of 18–27 years were adherent to medication, other studies have found that age had no significant effect on adherence. ⁵ However, Berk et al. stated that young age affects adherence negatively in patients with BPAD. ⁶ A few studies also report an improvement of medication adherence in older patients with schizophrenia. ⁷ Similar to other reports, demographic characteristics did not affect compliance. ⁸ In our study, there was better adherence among educated patients which is contrary to a study by Lacro et al. where it did not affect adherence. ¹ In our study, parental social support produces significantly greater compliance as they supervised the medicine intake at home and brought the patients for regular follow-ups.

Mild illness was associated with a significantly better medication adherence, particularly among those with schizophrenia, which supports the theory that those with severe psychopathology are less likely to comply with treatment. This suggests that the severity of the illness may have an impact on adherence. ² Lack of knowledge, lack of insight, poor awareness of the natural course of the illness and treatment outcomes were commonly stated as reasons for medication non-compliance. This is similar to that reported by Fenton et al. ²

Sedation was the most commonly reported side-effect which affected adherence negatively which is similar to that reported by Fenton et al. ² However, some caretakers of patients with BPAD did not necessarily consider it as adverse as it assisted the care-giving by allaying the patient's aggression or over-activity.

There may be other practical barriers to treatment compliance such as lack of money for medication or distance travelled to the hospital, but enabling factors, such as good availability of medicines at the hospital pharmacy, packaging and clear labelling of medicines, a good attitude of the doctors and the provision of counselling sessions by psychiatric social workers, can overcome these barriers.

Proper preparation for patients and their caregivers in the form of education about the treatment and medication, in particular, is associated with improved adherence to treatment, psychological well-being and quality of life. ⁹

Conclusion

Medication non-adherence in patients with mental disorders in an Indian setting has been under-studied and is a frequent cause of exacerbation and relapse. A high prevalence of medication non-adherence was found and a lack of awareness of the nature of the illness and its treatment was the most common reason for poor drug compliance. Factors associated with good medication adherence were younger age, good social support and a milder illness.