Comparison of adherence measures using claims data in the South African private health sector.

BACKGROUND: Medication adherence measurement is becoming increasingly important. Biological assays and markers, directly observed therapy, self-reports, pill counts and surveys have been successfully used to assess adherence under various circumstances, but may be limited by cost, ethical concerns and self-reported bias. Administrative claims data, in addition to offering a solution to these limitations, provide access to large study populations under real clinical practice situations, and in a timely and effective manner. With the wide range of adherence measures determined from claims data available - some of which have been found to be mathematically equivalent - researchers are often faced with the decision of choosing which is appropriate. An assessment of the various measures is therefore important for better understanding and to facilitate future adherence studies using administrative data. OBJECTIVES: To compare different adherence measures using data from a medicines claims database in South Africa (SA), employing montelukast for the purpose of illustration. METHODS: This retrospective, cross-sectional research used data from 1 January 2006 to 31 December 2015 from a privately owned pharmaceutical benefits management (PBM) company in SA. Claims for montelukast were identified and adherence was determined using the continuous multiple-interval measure of oversupply (CMOS), compliance ratio (CR), modified medication possession ratio (MPRm), refill compliance rate (RCR), continuous single-interval measure of medication acquisition (CSA) and proportion of days covered (PDC) capped at 1. The measures were compared with the medication possession ratio (MPR) as the reference. RESULTS: The MPR, CMOS and CR were equivalent, each yielding an adherence value of 86%. The MPRm, RCR and average CSA yielded higher adherence values of 96.9%, 117.2% and 129.0%, respectively, whereas the PDC produced a lower adherence value of 76.0%. The measures that used the entire study period as the denominator produced consistent results compared with the measures that used the difference between claims dates as denominator. CONCLUSIONS: The MPR is considered the most widely used metric to measure adherence using administrative data, but it may not always be applicable owing to the type of data available. Adherence computed using the CR, CMOS and PDC capped was found to be comparable to the MPR, and they may therefore be used as alternatives.

Inappropriate medicine prescribing in older South Africans: A cross-sectional analysis of medicine claims data.

BACKGROUND: Prescribing for older patients is a well-recognised problem, and inappropriate items are prescribed frequently. Several tools and criteria are available to promote rational prescribing in older patients. OBJECTIVE: To determine the prevalence of potentially inappropriate prescriptions (PIPs) in older South African patients. METHODS: A retrospective drug utilisation review was conducted using medicine claims data over a 1-year period. Patients aged ≥65 years with at least one paid claim for any medicine item during this period were included. The prevalence of PIPs was identified by applying the 2012-Beers criteria list. RESULTS: A total of 103 420 patients, mean age 74.0 years (standard deviation 6.7), 57.1% female, were included in the analysis. The number of PIPs identified was 562 852 in 71 206 patients (68.9%). The most common medicines inappropriately prescribed were oestrogen (oral and patch formulations only) (12.4%), meloxicam (7.3%), amitriptyline and combinations thereof (6.5%), diclofenac (6.4%), ibuprofen (6.1%), alprazolam (5.3%), meprobamate and combinations thereof (5.0%), sliding-scale insulin (3.3%), amiodarone (3.1%) and doxazosin (2.6%). Medicines were inappropriately prescribed to women statistically significantly more often than to men (1.9:1; p<0.001), although this difference was not of practical significance (Cramér's V=0.06). CONCLUSIONS: Medicine use in older patients must be appropriate and evaluated regularly. According to explicit criteria, PIPs were found to be common in older patients registered on the database. Monitoring of PIPs may increase the quality of prescribing, but explicit criteria cannot substitute for clinical judgement based on the individual patient.

Further Potential Savings Attributable to Maximum Generic Substitution of Antidepressants in South Africa: a Retrospective Analysis of Medical Claims

The main objective of the study was to calculate potential cost savings that could have been generated by maximum generic substitution of antidepressants within the private health care sector of South Africa from 2004 to 2006. Data on computerized medicine claims of patients receiving one or more antidepressants during three consecutive years (i.e. 2004; 2005 and 2006) were elicited from a South African pharmaceutical benefit management company. The total study population consisted of 292 071 items (N = 5 982 869) on 273 673 prescriptions (N = 5 213 765) at a total cost of R56 183 697.91 (N = R1 346 210 929.00). A quantitative; retrospective drug utilization review was conducted; and data were analyzed using the Statistical Analysis Systemr programme. Potential cost savings were computed for criteria-eligible substances in the study population. Generic medicine constituted 58.7(N = 292 071) of all antidepressants claimed; at a total cost of 28.2(N = R1 346 210 929.00) of all incurred costs. With total substitution of the average price of all criteria-eligible innovators; a potential saving of 9.3(N = R56 183 697.91) of the actual antidepressant cost over the study period was calculated. In developing countries with limited health care resources; generic medicines can be cost-saving treatment alternatives

Prescribing patterns of medicine classified as 'antidepressants' in South African children and adolescents

The main objective of this study was to characterise prescribing patterns of medicine classified as 'antidepressants' (hereafter simply referred to as antidepressants) in children and adolescents in the private health care sector of South Africa. A retrospective drug utilisation design was used to identify patients aged 19 years and younger from a South African pharmaceutical benefit management company's database; whom were issued at least one antidepressant between 1 January 2006 and 31 December 2006. Prescribed daily dosages (PDDs) were calculated using the Statistical Analysis Systemr program. A total of 1 013 patients received a mean number of 2.88 (SD 3.04) prescriptions per patient. Females received more prescriptions than their male counterparts; with the highest prevalence in the 15 = 19 years age group. The pharmacological groups most prescribed were the selective serotonin reuptake inhibitors (43.0) and the tricyclics (42.7); with imipramine (22.04) and amitriptyline (19) as the most commonly prescribed drugs. Approximately 30(n = 2 300) of all antidepressants in the study population were prescribed off-label. Amitriptyline and clomipramine were prescribed at daily dosages higher than recommended in children and adolescents aged 9 = 15 years. Lithium; trimipramine; trazodone and sulpiride were prescribed at sub-therapeutic dosages in adolescents. This study provided insight in the prescribing patterns of medicine classified as antidepressants in South African children and adolescents. These drugs; however; have many indications. Further research is needed to determine reasons why specific drugs are prescribed in this population

Investigation into the Prescribing Patterns and Cost of Antidiabetic Medicine in South Africa

"The general objective of this study was to investigate the prescribing patterns and cost of antidiabetic medicine in the private health care sector in South Africa by using a medicine claims database. A quantitative; retrospective drug utilisation study was performed on data for the year 2004. Oral antidiabetic medicine accounted for 81 (n =143 447) and 39 (R29 734 360.61) respectively of the total prevalence and cost of all antidiabetic products prescribed. Metformin was the most frequently prescribed oral antidiabetic medicine; with an average cost of R58.42 (SD = 31.78). The three most frequently prescribed classes of insulin (insulin lispro; soluble insulin and isophane; and soluble insulin aspartame and protamine) together accounted for 63 of all the insulin prescribed; and 67 of the total cost of prescribed insulin. Almost 39 (n = 62 717) of the ""combination therapy"" prescriptions were for a sulfonylurea in combination with a biguanide plus at least one other antidiabetic product. A trend towards combination therapy away from monotherapy was observed. Prescribed Daily Doses (PDDs) calculated for oral antidiabetic medicines were more or less in line with recommended treatment guidelines. Drug utilisation review studies thus provide valuable insight into the treatment of diabetes - indicating areas of possible over- and under usage; providing decision-makers with critical information to curb unnecessary costs."