Cost of Illness of Schizophrenia from Societal Perspective. A Case Study of Khyber PakhtunKhwa Pakistan.

Abstract

Cost of illness studies (COI) are used to quantify the disease burden and equip the policy makers with effective decisions regarding resource allocation for this purpose a cost of illness study of schizophrenia using societal perspective was conducted. The objectives of the study were to quantify annual direct and indirect cost of schizophrenia, to evaluate antipsychotic prescription patterns and cost of antipsychotics and recognize the impact of antipsychotics non-adherence and antipsychotic side effects on overall cost of schizophrenia. Prospective observational multicenter prevalence based COI approach was used. 100 Patients of both genders with a diagnosis of schizophrenia were enrolled in the study. Data was collected through a structured interview of patient and patient attendant. Once diagnosed by the consultant psychiatrist in outpatient department the patients were then interviewed about the financial burden of disease. Patients and attendants were required to keep complete medical records during the 1-year course of the study and to complete the questionnaire at 4, 8, and 12 months, for a total of three assessments during follow up visits. Direct cost was quantified using micro costing bottom up approach. Indirect cost was defined as a lost production by patient due to illness or looking after a sick patient by hospital attendant or home caregiver. Indirect cost in the present study was quantified by Human capital approach. Economic perspective of present study is societal. In present study patient’s adherence to medication was monitored using 4- item Morisky Medication Adherence Scale (MMAS). The MMAS was administered to patients in the presence of their attendants in the last follow-up of the study. Antipsychotics induced side effects were screened by using Abnormal Involuntary Movement Scale (AIMS) and Liver pool University Neuroleptic Side Effect Rating Scale (LUNSERS). Both AIMS and LUNSERS were administered to patients in the last follow up visit. A total of 72 patients out of 100 patients were included in the final analysis, out of total 72 patients 66.7 % were male, mean age of patients was 33.6 years, average monthly income of patients was PKR: 11747.2 Pakistani rupees, equivalent to US$: 115. Mean Positive and Negative Syndrome Scale Score was 77.6. Mean duration of illness was 2.9 years; 51.4 % patients avail inpatients facility during one year study duration upon severity of illness. Mean number of inpatient stay was 9.3 days. Estimated total annual cost per case is (Rs.) 88589 Pakistani rupees, equivalent to US$ 868 (1 US$ = 102 Rs). The Direct cost is Rs. 46760 (52 %) and forms the bulk of total cost. Inpatient care accounts for 31.8 % (Inpatient consultation, stay, ECT, Psychotherapy, medical board, liaison consultation) of direct cost followed by pharmacotherapy cost (21.25 %) and overhead cost (15.8 %). The mean annual indirect cost per patient (Rs. 41829, US$: 429) accounts for 47.2 % of total cost. Indirect cost born by the patient’s represents nearly half (45.9 %) of total indirect cost, followed by home caregiver cost (30.1 %). Using independent sample t-test it was observed that total cost, direct cost, direct medical cost, direct nonmedical cost and indirect cost born by patients, hospital attendants and home caregiver were significantly higher for those patients who availed inpatient facility compared to outpatient (p < 0.05). Pearson correlation shows significant positive correlation of total cost and direct cost with PANSS (p < 0.01). Highly significant correlation was observed among number of drugs prescribed to each patient and total cost and direct cost (p < 0.01). Highly significant correlation of total cost, direct cost, and indirect cost was observed with inpatient stay, abbsentism and monthly income of patients (p < 0.01). Significant negative correlation was observed among duration of illness and total cost and direct cost (p < 0.05). Linear regression analysis shows most significant predicator of total cost is inpatient stay (p < 0.01). For the entire sample population, the mean annual cost of antipsychotics prescribed Rs. 8079. For SGAs used alone, the mean annual cost was Rs. 8110. For FGAs used alone, the annual cost was Rs. 2554. For a combination of SGAs and FGAs, the mean annual cost was Rs. 9528. Statistically significant difference was observed among cost of different antipsychotic classes using one-way ANOVA [F (2, 68) = 4.6 p = 0.013]. Post Hoc LSD test shows significant cost difference among SGA and FGA (p < 0.05) and cost of combination (FGA + SGA) was significantly different from FGA (p < 0.05). Results show that 29.1 % patients were non- adherent to medications. Independent sample t-test was used to find significant difference in cost categories among two groups. Highly significant difference was observed in indirect and total cost among two groups (p < 0.01). Indirect Cost born by patients, attendants and home caregiver were significantly higher in non-adherent patients compared with adherent patients (p < 0.01). In the present study 20.8 % patients score positively on AIMS scale for tardive dyskinesia. AIMS positive patients incurs high cost compared with AIMS negative patients, however using t-statistics the mean annual cost difference is not statistically significant. Mean annual indirect cost of home care giver is significantly high for AIMS positive patients (p < 0.05).