Differential Diagnosis Framework for Nurse Practitioners
Systematize differential diagnoses with SNAP-based clinical reasoning framework
What You Can Do
You can build comprehensive, defensible differential diagnoses for complex patient presentations by working with Claude to organize clinical thinking, identify missing information, and prioritize diagnostic testing. The framework uses modified SNAP methodology (Symptom → Narrow → Assess → Prioritize) combined with likelihood ratio thinking to move beyond pattern recognition to systematic evaluation. This helps you justify clinical decisions, strengthen documentation for chart audits, and manage diagnostic uncertainty in busy clinical settings.
Features
Symptom categorization, Narrowing by pathophysiology, Assessment of red flags, Prioritization by likelihood ratios
Systematic screening for life-threatening diagnoses requiring immediate action or referral
Quantify how clinical findings shift probability of diagnoses, moving beyond intuition
Identify missing history, physical exam findings, or testing needed to rule in/out key diagnoses
Build evidence-based testing sequences that balance diagnostic yield, cost, and patient safety
Ensures differential and workup recommendations fit NP independent and collaborative practice models
Generate clinical reasoning statements demonstrating systematic thinking for medical record and chart audits
Works across undifferentiated presentations (chest pain, abdominal pain, dyspnea, altered mental status)
Example Output
Example 1: Chest Pain Presentation
Patient: 52-year-old male with 3 hours substernal pressure, diaphoresis, left arm radiation
SNAP Analysis:
- Symptom: Acute substernal chest pain with typical ACS features
- Narrow: Cardiac (ACS, aortic dissection), pulmonary (PE), GI (GERD), MSK (unlikely given presentation)
- Assess Red Flags: ECG changes present? Hemodynamic instability? Hypoxia? → Determines emergent vs. urgent pathway
- Prioritize: (1) Troponin + serial ECG (highest pre-test probability for ACS), (2) Chest X-ray (PE, aortic pathology), (3) D-dimer if PE suspected
Diagnostic Gaps Identified: Need ECG interpretation, troponin baseline, vital sign trends over next 3 hours
Example 2: Chronic Abdominal Pain (Complex Case)
Patient: 38-year-old female with 6 months intermittent epigastric/RUQ pain, normal recent imaging
Differential by Likelihood:
- Functional dyspepsia (most common, normal imaging) — requires Rome IV criteria review
- Sphincter of Oddi dysfunction (consider if imaging normal) — controversial diagnosis, referral consideration
- Chronic pancreatitis (less likely without amylase elevation) — needs fecal elastase assessment
- Unrecognized GERD (redefined as extraesophageal) — trial PPI diagnostic approach
Diagnostic Gaps: Detailed symptom characterization (triggers, timing), medication review (NSAIDs?), alarm feature assessment, previous testing documentation
Recommended Workup Path: Establish diagnosis of exclusion first (repeat CBC, CMP, lipase if not recent) → Consider empiric PPI trial vs. gastroenterology referral based on alarm features and patient preference
What's Included
- SKILL.md instruction file: Complete framework with SNAP methodology, likelihood ratio approach, and red flag protocols
- SNAP Assessment Template: Structured worksheet for organizing symptoms, narrowing differentials, and identifying gaps
- Red Flag Screening Checklist: Quick reference for life-threatening diagnoses requiring immediate action across common presentations
- Diagnostic Workup Prioritization Matrix: Framework for sequencing testing by likelihood, yield, and cost-effectiveness
- Documentation Template: Clinical reasoning statements demonstrating systematic thinking for EMR and chart audit support
Who It's For
- Nurse Practitioners in primary care — managing undifferentiated complaints and complex chronic disease
- Acute care/urgent care NPs — triaging acute presentations with diagnostic uncertainty
- Specialty NPs (cardiology, gastroenterology, pulmonology, etc.) — complex cases outside subspecialty expertise
- NP residents and students — building systematic clinical reasoning during training
- NPs in medically underserved settings — managing complex patients with limited specialist access
Best For
- Undifferentiated acute presentations (chest pain, abdominal pain, dyspnea, altered mental status)
- Complex chronic disease with multiple comorbidities and atypical presentations
- Cases requiring documentation of systematic reasoning for chart audits or medical-legal review
- Diagnostic uncertainty when considering in-office management vs. specialist referral
- Building confidence in clinical reasoning before patient encounters or during new practice settings
You might also like
You conduct comprehensive pre-operative risk stratification using ASA classification, Revised Cardiac Risk Index (RCRI), and procedure-specific risk tools to quantify operative risk across physiologic systems. You systematically identify modifiable risk factors—anemia, hypertension, glucose dyscontrol, cardiac dysfunction—and implement targeted optimization protocols to reduce preventable complications. You generate objective, evidence-backed assessments that strengthen informed consent discussions, support case selection decisions, and create defensible documentation for shared decision-making with patients and surgical teams.
by gptomics
You'll systematically evaluate patient risk factors, stratify perioperative risk using evidence-based frameworks, and generate detailed anesthesia plans that address specific comorbidities and procedural requirements. This skill helps you synthesize complex patient data—medical history, physical exam findings, lab work, imaging, and medication profiles—into actionable risk mitigation strategies that optimize patient safety and guide technique selection, drug choices, and monitoring protocols.
by gptomics
You can rapidly develop theoretically-grounded case formulations that integrate diagnostic findings, historical context, and clinical observations into a coherent narrative. The skill systematizes your conceptualization across multiple therapeutic modalities (CBT, psychodynamic, trauma-informed, systemic) and generates structured treatment plans with specific goals, interventions, and prognostic considerations—ideal for supervision presentations, case conferences, documentation, and complex diagnostic scenarios.
by gptomics
You can systematically document refraction findings for low vision patients and generate prescriptions optimized for specific functional tasks like reading, mobility, and facial recognition. The skill calculates appropriate magnification ratios, predicts realistic visual outcomes, and creates comprehensive documentation that prioritizes quality of life over distance acuity—transforming conventional refraction into patient-centered, task-driven prescriptions.
by gptomics
You can rapidly analyze multifaceted surgical presentations—including revision cases, comorbidities, and combined pathology—to develop defensible pre-operative plans and detailed operative notes. The skill synthesizes clinical findings with imaging data, stratifies surgical risk, selects technique-specific approaches, and produces documentation that withstands peer review and quality audits.
by gptomics
You can perform structured sports injury evaluations that incorporate mechanism-of-injury analysis, orthopedic special testing, functional movement screening, and clear referral criteria. The skill helps you differentiate soft tissue restrictions from joint dysfunctions, establish baseline function, and create evidence-based return-to-play milestones tailored to the athlete's sport and position. You'll generate documentation suitable for insurance records, team physician communication, and liability protection.
by gptomics
You can conduct comprehensive subluxation assessments on pediatric patients by integrating structural examination findings, functional limitations, parental observations, and neurological indicators within a developmental context. Claude helps you correlate specific subluxations to presenting complaints (colic, ear infections, torticollis, scoliosis patterns) and create objective documentation suitable for insurance, medical records, and referral purposes. You'll develop age-appropriate treatment plans that address both the subluxation and the child's unique physiological stage.
by gptomics
You can systematically generate ranked differential diagnoses for presenting complaints (chest pain, dyspnea, abdominal pain, headache, joint pain, fatigue) by applying evidence-based clinical decision rules and risk stratification. The skill helps you identify red flags that change management priority, justify test selection to supervising physicians, and document diagnostic reasoning in the medical record while reducing anchoring bias and ensuring comprehensive consideration of serious diagnoses.
by gptomics