· To compare the SBP (Systolic Blood Pressure) at 0 and 12 months among hypertensive patients randomized to receive the DSS or the chart based algorithmic support system

· To compare the Quality of Life (QoL) scores at 0 and 12 months among hypertensive patients randomized to receive the DSS or the chart based algorithmic support system

· To compare the Cost effectiveness of the DSS versus the chart based algorithmic support system at the end of 12 months among hypertensive patients.

· To compare the Cost utility of the DSS versus the chart based algorithmic support system at the end of 12 months among hypertensive patients.

1. Adult male and female Indians in the age group of 35 – 64 years

2. Systolic blood pressure (SBP) of 140 mm Hg or greater and/or diastolic blood pressure (DBP) of 90 mm Hg or greater (irrespective of antihypertensive medications)

3. Informed written Consent form

Hypertensive subjects who have been hospitalized within the last 12 months and subjects with a history of cancer (physician certified).

Randomly chosen Primary Health Care centers (PHCs), matched on population size and literacy rate, from a district in the state of Andhra Pradesh, India have been cluster randomized to receive a DSS or a chart based algorithmic support system (Figure 1). The study site, Mahabubnagar district (AP) has four revenue divisions (Wanaparthy, Nagarkurnool, Gadwal and Narayanpet). Demographic details of all the PHCs, stratified by the revenue divisions in Mahabubnagar district, were line listed. The male to female ratio, age group distribution in the PHCs (based on census 2001 data) will be collected from the Andhra Pradesh State Health and Revenue departments. The PHCs will be stratified based on similarity in the study age group demography details (35-64 years of age) and gender distribution. Two PHCs, per intervention arm, will be randomly chosen from each of the four divisions.

Physicians from the PHCs, who have been randomised to receive the DSS arm would necessarily be trained and instructed to follow the algorithms and prompts which would arise out of the computer based software, for management of BP. DSS is a software that helps the Physician to (1) undertake a thorough evaluation of risk factors that hypertensive patients may have for developing a cardiovascular disease, (2) to classify the risk level, (3) to follow a software prompted algorithmic guideline based drug management (which would be developed based on Indian Hypertension guidelines II – 2007) and (4) to give alerts on the counselling on lifestyle changes and adherence to medication.

The chart based algorithmic support system will have the guidelines and lifestyle advices printed as a poster format which would then be pasted on the wall of the PHC clinics. The Physicians from the PHCs, who have been randomised to receive the chart based support arm, would be instructed to follow the poster based guidelines for management of BP. The risk factors that need to be specifically elicited, classification of risk among hypertensive subjects, flow chart for drug management and advice for lifestyle interventions would be included as a simple flow chart.

The DSS will be developed, pilot tested in 10% of sample size and then implemented. Physician advice on lifestyle interventions, which would include counselling on reduction of daily salt intake (reduction in papad and pickle intake) and locally relevant fatty food items (ghee, vanaspati and dalda), advice on benefits of brisk walking for 30 min daily (5-7 days in a week), advice on benefits of smoking cessation and adherence to treatment would be available for patients randomized to DSS intervention arm at 0, 6 and 12 months and at 0 month for patients randomized to receive chart based algorithmic support system. Physical measurements such as height, weight, waist circumference, pulse and Blood Pressure (BP) would be measured by a digital BP monitor at 0, 6 and 12 months after study entry (Figure 2).

A third party payer perspective will be employed in this project, as this would enable the tangible costs to be directly compared between both the intervention arms.

The value of all goods, services, and other resources consumed in providing health care or dealing with side effects or other current and future consequences of health care comprise the direct costs. Direct health care and direct non health costs will be measured in this study. The physician services, hospital services, drugs, costs of the DSS software development, costs for charts (posters) etc. involved in delivery of health care would comprise the direct health care costs. Transportation to and from the site of care would comprise the indirect costs. Marginal costs analysis would be done in which how outcomes change with changes in costs (e.g., relative to a comparator), would be analysed. The time horizon for the costs involved would be for a duration of a year.

A reduction or worsening of systolic BP would be compared (in non monetary terms). The time horizon would be for a duration of one year.

Thus, costs and outcomes will be discounted relative to their present value (e.g., at a rate of three - five percent per year) so as to account for the effect of time on the value of the outcomes and costs, as they may have less value in the future. Opportunity costs, which would be reflected by discounting, would also be calculated.

Since any estimation of costs and outcomes has an uncertainty element attached to it, a sensitivity analysis, which would include a change in discount rates, would be done to account for the changes in the cost-effectiveness planes of one intervention compared to another.

The costs and outcomes for both the outcomes will be calculated to yield a CER.

CER = { Cost of DSS – Cost of chart based / ( Primary outcome of DSS – primary outcome of chart based intervention ) }

Table 1 gives the details of the sample size calculations. To detect a difference of 4 mm Hg Systolic Blood Pressure (SBP), the individual randomization sample size has been calculated at 239 subjects per intervention arm (SD of 19.5 mm for SBP 22), with a 80% power and an alpha of 0.05. Since, cluster randomization is being attempted in this study, the individual randomization sample size has to be adjusted by a design effect of 2.98 [design effect = 1+ (size of cluster -1) * Intra cluster Correlation (ICC)]. The ICC for the clusters among the Mahabubnagar district, AP, India (study site) has been calculated to be 0.02 (based on the Indian sentinel surveillance study done on a representative sample from 10 sites in India). Hence, the cluster adjusted sample size is 713 hypertensive patients (8 clusters with 125 subjects in each cluster to allow for a 20% loss to follow up) per intervention arm to detect a 4 mm Hg difference in Systolic Blood Pressure (SBP) with a power of 80% and an alpha of 0.05. After adjusting for the coefficient of variation among the various clusters (CV = 0.25), the sample size per intervention arm is 741, i.e. a total of 8 clusters (with equal cluster size of 100 each) would be required per intervention arm.

ICC = Intra Cluster correlation; DE = design effect; CV = coefficient of variation.

Randomly chosen 8 PHCs – 4 urban and 4 rural (homogenous in age and gender distribution) for each intervention arm from a district in the State of AP, India would form the study centers. Each PHC has an out patient load of 50-100 patients/day. 2- 4 hypertensive patients are being envisaged to be recruited per day by the Physician per PHC from the patients attending the out patient clinic in the PHC. 10- 20 patients per week per PHC, 20- 40 per month per PHC and 125 patients in 4-6 months. Study recruitment will last from June 2011 to Dec 2011.

The participants would be given sufficient time to understand the contents of the PIS (containing the study purpose, duration, study procedures, right to withdrawal from the study, details of patient confidentiality, ethical committee clearances, the study team details), and encouraged to ask questions regarding any aspects of the study procedures that they have not understood. The written informed consent form will be read out aloud in the native language to the study participants. They will be given an opportunity to seek clarifications on any issues that have not been understood. The signatures would be obtained by the Physician who would be recruiting the hypertensive patients for the study. The Physician would also sign and date the informed consent form. One copy would be given to the patients and one copy would be retained at the study site.