HLTH 6880 Week 6 Social Venture Theory of Change Example

LinkBP Theory of Change: From a Screening Reading to Controlled Blood Pressure, With Every Assumption Written Out

Student Name

Walden University

HLTH 6880: Social Entrepreneurship and Innovation: A Global Perspective

Instructor Name

Month Day, Year

LinkBP Theory of Change: From a Screening Reading to Controlled Blood Pressure, With Every Assumption Written Out

Introduction

LinkBP's theory of change runs from a follow-up worker and a blood pressure cuff to fewer strokes and heart attacks among rural adults in a composite western Kenya county. Stated in one line: if a named worker follows each referred adult from screening to clinic and visits monthly afterward, more referred adults will reach care, stay in it and reach controlled blood pressure, and over years fewer will suffer cardiovascular events. This paper sets out each box in that chain and, more importantly, the assumption between each pair of boxes, with evidence where it exists and a plan to test it where it does not. Evidence-building guidance for social sector organizations recommends exactly this: a clear theory of change is the basis for deciding what to measure and what not to (Gugerty & Karlan, 2018). A table summarizing the chain appears below.

The Chain at a Glance

Table 1 lists the chain from inputs to long-term change. Each arrow carries an assumption, set out in the sections that follow.

Table 1

LinkBP Theory of Change (Composite Venture)

From Inputs to Activities

The inputs are follow-up workers recruited from the sub-county, one supervisor per group of workers, validated automatic cuffs, phones with a case-tracking application and an agreement with county clinics to confirm visits and share refill dates. Activities are specific: each worker enrolls adults at screening events, visits within seven days, books and confirms a clinic visit within 30 days, checks blood pressure monthly at home or work and sends a prompt when a refill is due.

Assumption 1: workers recruited locally can be trained to take accurate readings and keep reliable records, and will do so consistently when supervised. Evidence on community health worker programs supports this when workers have defined tasks, supportive supervision and pay; World Health Organization guidance recommends all three (World Health Organization, 2018). LinkBP pays workers and gives them one task, which reduces the risk that hypertension follow-up is crowded out by other duties.

From Activities to Outputs

Outputs count what LinkBP produces: adults enrolled, first clinic visits confirmed, monthly checks completed and refill prompts sent.

Assumption 2: workers can reach their caseloads at the planned frequency in rural terrain and in the rainy season. This is untested for LinkBP. In the composite county, an illustrative caseload would allow each worker to reach most adults within a day's travel, but the assumption will be checked during the first quarter by comparing completed checks with planned checks per worker. If completion falls below about four in five, caseloads will be cut.

From Outputs to the Short-Term Outcome

The short-term outcome is that referred adults reach a clinic within 30 days.

Assumption 3: personal follow-up by a worker increases the share of referred adults who reach care. The most relevant evidence is the western Kenya trial in which community health workers used tailored behavioral communication, with or without smartphones. Linkage to care was 49% overall, and it was significantly higher in the usual-care and smartphone arms than in the paper-based arm (Vedanthan et al., 2019). The evidence supports the assumption that how workers follow up matters, but it also warns that adding a new communication tool can make linkage worse, not better. LinkBP's design responds by making a confirmed clinic booking, not a conversation, the core activity, and by measuring linkage from the first month.

From the Short-Term to Medium-Term Outcomes

The medium-term outcomes are that adults are still collecting medicine at 12 months and that their readings are below 140/90 mm Hg.

Assumption 4: continued home visits linked to public clinics lead to better blood pressure control over time. The strongest evidence comes from a cluster randomized trial in rural Bangladesh, Pakistan and Sri Lanka, where trained government health workers visited homes proactively for blood pressure monitoring and counseling, linked with physician training and care coordination in the public sector. At 24 months, systolic pressure fell by 5.2 mm Hg more in intervention communities than in control communities, and 53.2% of participants reached control below 140/90 mm Hg, compared with 43.7% under usual care (Jafar et al., 2020). That is evidence for a comparable mechanism in a different region, so it supports the assumption without proving it for western Kenya.

The western Kenya trial adds a caution: reaching care did not by itself produce a significant difference in systolic pressure between arms (Vedanthan et al., 2019). LinkBP therefore treats the move from linkage to control as an assumption that requires continued follow-up, and medicine supply at the clinic, rather than as an automatic result.

From Medium-Term Outcomes to Long-Term Change

Assumption 5: lowering blood pressure in this population will reduce cardiovascular events. This is well supported in general clinical evidence and underlies the treatment recommendations of the World Health Organization's 2021 hypertension guideline (World Health Organization, 2021). LinkBP cannot test it directly; the number of events in one sub-county would be too small to detect a change over a few years. The venture will therefore report blood pressure control as its main outcome and describe the long-term change as the reason control matters, not as a result it can claim.

What Remains Untested

Two links are untested for LinkBP: whether workers can reach caseloads at the planned frequency, and whether county clinics will keep antihypertensive medicine in stock so that follow-up has something to follow up to. A third, that monthly checks lead to control in this setting, is supported by a comparable trial but not by local evidence. Each will be tested in the pilot year, through the measurement plan set out in Week 8. If clinic stock-outs prove common, the theory of change would need a new activity, such as a supply arrangement with the county pharmacy, before LinkBP could expect control to improve.

References

Gugerty, M. K., & Karlan, D. (2018). The goldilocks challenge: Right-fit evidence for the social sector. Oxford University Press.

Jafar, T. H., Gandhi, M., de Silva, H. A., Jehan, I., Naheed, A., Finkelstein, E. A., Turner, E. L., Morisky, D., Kasturiratne, A., Khan, A. H., Clemens, J. D., Ebrahim, S., Assam, P. N., & Feng, L. (2020). A community-based intervention for managing hypertension in rural South Asia. New England Journal of Medicine, 382(8), 717-726. https://doi.org/10.1056/NEJMoa1911965

Vedanthan, R., Kamano, J. H., DeLong, A. K., Naanyu, V., Binanay, C. A., Bloomfield, G. S., Chrysanthopoulou, S. A., Finkelstein, E. A., Hogan, J. W., Horowitz, C. R., Inui, T. S., Menya, D., Orango, V., Velazquez, E. J., Were, M. C., Kimaiyo, S., & Fuster, V. (2019). Community health workers improve linkage to hypertension care in western Kenya. Journal of the American College of Cardiology, 74(15), 1897-1906. https://doi.org/10.1016/j.jacc.2019.08.003

World Health Organization. (2018). WHO guideline on health policy and system support to optimize community health worker programmes. World Health Organization.

World Health Organization. (2021). Guideline for the pharmacological treatment of hypertension in adults. World Health Organization.