The  Behavioral Stability Assessment  (BSA™) was developed to fill a critical gap in adherence measurement: the lack of a behaviorally anchored, time-bound instrument that captures a patient’s actual medication-taking behavior in a specific, recent timeframe. Existing scales primarily rely on present-tense perception-based items, which can introduce recall bias, optimism bias, and psychometric inconsistencies. The BSA™ addresses these limitations by focusing on past-week concrete behavior, providing a precise “snapshot” of adherence.

Where the BAS™ measures predictive stability; essentially the “video” of where a patient is heading, the BSA™ captures the retrospective reality, the “still photograph” of what has already occurred. Together, they form a dual-lens system that grounds adherence assessment both in predictive modeling and in lived behavioral evidence. 

Methodology & Conceptual Foundation

Behavioral science demonstrates that past behavior is the best predictor of future behavior. To be scientifically valid, questions about past behavior must be specific, time-anchored, and behaviorally observable. The BSA™ situates all questions in the past 7 days, avoiding vague “sometimes” or “ever” phrasing that can create psychometric noise. The instrument was developed following these guiding principles:

1. Distinct Domains: Each of the items measures a unique domain of adherence, avoiding redundancy and maximizing internal consistency.
    
2. Intentional vs. Unintentional Nonadherence: The BSA distinguishes behaviors patients' control (intentional) from lapses due to forgetfulness or logistical barriers (unintentional). This distinction is actionable for clinicians: intentional behaviors may require motivational or therapeutic intervention, while unintentional lapses benefit from practical reminders or support.
    
3. 1:1 Alignment with BAS: Each BSA item is conceptually paired with a BAS item, creating a yin-yang complementarity: the BAS anticipates stability, while the BSA verifies adherence in real time.
    
4. Past-Tense Anchoring: All items are framed in past tense, increasing recall accuracy, minimizing optimism bias, and providing a concrete behavioral record.

Before You Begin

This is not a test. There are no right or wrong answers.
Everyone manages medications and routines differently. These assessments are designed to understand patient experiences, identify patterns, and guide supportive care.

Responses are confidential and should always be as honest as possible.

Each question uses triadic scoring:

• No = 1.0
   
• Yes, once = 0.5
   
• Yes, more than once = 0.0 

Answer each question as honestly as possible, even if your answer is “Yes, more than once.” Think about your recent experiences when you choose a response. Remember that your information is confidential and will only be used to guide your care.

1 — Routine
In the past 7 days, did you have trouble taking your medication at the same time each day?
☐ No ☐ Yes, once ☐ Yes, more than once

2 — Memory
In the past 7 days, did you miss any doses?
☐ No ☐ Yes, once ☐ Yes, more than once

3 — Symptom response
In the past 7 days, did you skip or stop taking medication because you felt better?
☐ No ☐ Yes, once ☐ Yes, more than once

4 — Side-effects response
In the past 7 days, did you stop or skip medication because of side effects?
☐ No ☐ Yes, once ☐ Yes, more than once

5 — Environment
In the past 7 days, did travel, being away, or your environment cause you to miss medication?
☐ No ☐ Yes, once ☐ Yes, more than once

6 — Flexibility
In the past 7 days, did you have difficulty adjusting your routine to take medication when your schedule changed?
☐ No ☐ Yes, once ☐ Yes, more than once

7 — Integration
In the past 7 days, did taking medication feel like a hassle or not fit naturally into daily life?
☐ No ☐ Yes, once ☐ Yes, more than once

• Intentional Non-Adherence (INA) Items:
   
  • Q3 Symptom response
     
  • Q4 Side-effects response
     

BSA_norm     Raw Score (0–7)      Descriptor                           Interpretation     

0.00–0.25     0.0 – 1.75                      Highly Prone                     Adherence very limited; 

0.26–0.50     2.0 – 3.5                         Unstable                              Multiple lapses; inconsistent behavior

0.51–0.75     3.5 – 5.25                      Moderately Steady      Mostly adherent; occasional lapses

0.76–1.00    5.25 – 7.0                      Reliable                                Strong adherence; few or no lapses 

The BSA™ represents a novel approach to adherence measurement. It is not a replication of existing scales but instead captures real-time adherence, providing a concrete behavioral snapshot that complements the predictive insights of the BAS™ and enables calculation of the Behavioral Stability Index (BSI™). Its eight distinct domains, unified response structure, and past-tense framing support strong psychometric integrity, providing us with a high internal consistency, accurate recall, and construct validity. By distinguishing between intentional and unintentional lapses, the instrument provides actionable insights for clinicians, allowing interventions to be tailored to the specific type of nonadherence observed. The BSA can function as a standalone measure of snapshot adherence or be paired with the BAS for a dual assessment that combines predictive modeling with retrospective behavioral verification.
 

BAS= video of where the patient is going
BSA = snapshot of where the patient has been
Together → BFS = geometric, actionable metric of behavioral fragility.
 

The BSA™ is the intellectual property of Philip Morisky and is exclusively distributed through Adherence Cartography. Unauthorized use, reproduction, or distribution is strictly prohibited.