Managing Formulary Evaluations

Managing Formulary Evaluations

Structures drug formulary reviews with efficacy, safety, cost-effectiveness, and therapeutic interchange analysis for Pharmacy and Therapeutics (P&T) Committee decision-making.

Why This Skill Exists

Hospital formularies directly impact patient outcomes, medication safety, and institutional costs. The Pharmacy and Therapeutics (P&T) Committee is the governance body responsible for evidence-based medication selection, and formulary monographs are the primary decision documents that inform their votes. ASHP guidelines mandate that formulary management be based on clinical evidence, not solely on cost. The Joint Commission and CMS require that hospitals maintain a formulary system with processes for evaluating and selecting medications.

A poorly structured formulary evaluation can lead to adoption of inferior agents, therapeutic duplication, unnecessary expenditure, or rejection of genuinely beneficial innovations. Conversely, rigorous monographs that address efficacy (with NNT), safety (with NNH), pharmacokinetic advantages, cost-effectiveness (ICER), and place in therapy relative to existing alternatives enable P&T Committees to make sound, defensible decisions. Pharmacists are the principal authors of formulary evaluations and therapeutic interchange protocols in virtually every health system.

Checkpoint A: Pre-Draft Intake (Mandatory)

1. What is the drug being evaluated (brand name, generic name, manufacturer)? (Default: specify)
2. Is this a formulary addition request, a therapeutic class review, or a formulary deletion? (Default: addition)
3. Who submitted the request (physician, service line, pharmacy)? (Default: document requestor)
4. What is the proposed indication and patient population? (Default: FDA-approved indication)
5. What are the current formulary alternatives for the same indication? (Default: review existing formulary)
6. What is the anticipated volume of use (patients/year)? (Default: estimate from requestor)
7. Is there a therapeutic interchange opportunity? (Default: evaluate)
8. What is the timeline for P&T Committee presentation? (Default: next scheduled meeting)

Documents to Request

• FDA-approved labeling (package insert) for the agent under review
• Pivotal clinical trial publications (Phase III trials)
• Systematic reviews and meta-analyses if available
• Comparative effectiveness studies vs. current formulary agents
• AMCP dossier or manufacturer-provided clinical evidence package
• Drug pricing: WAC, 340B, GPO contract pricing, and net-cost-per-course
• Current formulary agents with their utilization data
• Published clinical practice guidelines mentioning the agent

Step 1: Drug Overview and Regulatory Status

Document the following:

• Generic name / Brand name / Manufacturer
• FDA approval date and approved indication(s)
• Pharmacologic class and mechanism of action
• Dosage forms, strengths, and storage requirements
• DEA schedule (if applicable)
• REMS program requirements (if applicable)
• Orphan drug or breakthrough therapy designation (if applicable)
• Patent expiration and anticipated generic/biosimilar availability

Step 2: Clinical Efficacy Analysis

Summarize evidence from pivotal trials using PICO framework:

For each key trial:

• Trial name and design (RCT, open-label, non-inferiority, superiority)
• Population: Inclusion/exclusion criteria, sample size, demographics
• Intervention vs. Comparator: Doses, duration, permitted concomitant therapies
• Primary outcome: Effect size with 95% CI, p-value, NNT
• Secondary outcomes: Clinically meaningful endpoints
• Limitations: Risk of bias, funding source, generalizability

Critical appraisal checkpoints:

• Was the comparator the current standard of care (not placebo when active comparator exists)?
• Was the trial powered for the primary endpoint?
• Were patient-important outcomes measured (mortality, hospitalization) vs. surrogate markers?
• Was intention-to-treat analysis used?
• What was the dropout rate and was it balanced between arms?

Step 3: Safety and Tolerability Assessment

Calculate NNH for significant adverse effects when data permits. Compare discontinuation rates due to adverse effects between the new agent and comparators.

Step 4: Pharmacoeconomic Analysis

Cost comparison structure:

Pharmacoeconomic metrics:

• Incremental cost-effectiveness ratio (ICER) if published
• Budget impact analysis for estimated institutional volume
• Cost-avoidance opportunities (reduced monitoring, shorter LOS, fewer adverse events)
• 340B implications if applicable (contract pharmacy, mixed-use settings)

Step 5: Place in Therapy and Recommendation

Synthesize all evidence into a clear formulary recommendation:

1. Place in therapy: First-line, second-line, alternative, or restricted use
2. Advantages over current formulary agents: Efficacy, safety, convenience, or cost
3. Disadvantages: Cost premium, safety signals, limited long-term data, administration complexity
4. Proposed formulary status:
   • Unrestricted (available to all prescribers)
   • Restricted (criteria for use, specialist-only, prior authorization)
   • Non-formulary (reject addition with rationale)
5. Therapeutic interchange protocol if applicable (automatic substitution criteria)
6. Criteria for use if restricted (diagnosis, prior treatment failure, specialist approval)

Checkpoint B: Post-Draft Alignment (Mandatory)

1. Is the comparator the current institutional standard of care, not just the manufacturer-selected comparator?
2. Are efficacy data presented with absolute measures (NNT) rather than only relative risk reduction?
3. Is cost analysis based on institutional contract pricing, not WAC alone?
4. Are restrictions clearly defined with measurable criteria (not vague "as deemed appropriate")?
5. Has the monograph been reviewed by a clinical pharmacist outside the requesting service?

Quality Audit

• FDA-approved indication matches the requested formulary use
• Pivotal trial data includes NNT/NNH calculations
• Comparator selection reflects current standard of care
• Off-label use is identified and evidence level documented
• Safety profile includes black box warnings and REMS requirements
• Cost analysis uses institutional contract pricing (not only WAC)
• Budget impact is estimated for the first 12 months of formulary addition
• Therapeutic interchange is proposed where clinically equivalent alternatives exist
• Criteria for use are measurable and auditable
• Monitoring requirements are detailed with lab parameters and frequency
• Drug interaction profile is assessed against commonly co-prescribed formulary agents
• Presentation follows institutional P&T monograph template
• Conflict of interest disclosure is included for monograph author

Guidelines

• Always present both absolute and relative efficacy measures; NNT is more actionable than relative risk reduction
• Use institutional contract pricing for economic analysis; WAC overstates cost for most health systems
• Include all relevant costs: acquisition, preparation, administration, monitoring, and adverse event management
• Therapeutic interchange protocols must include clinical equivalence justification and prescriber notification process
• Formulary restrictions should have measurable, auditable criteria—avoid subjective language
• Assess implications for medication safety (LASA potential, high-alert status, storage requirements)
• Consider 340B program impact when the agent will be used in eligible settings
• Update the formulary monograph when significant new evidence emerges (post-marketing studies, safety signals, generic availability)