Cost Effectiveness AnalysisTo Enhance Mammography Use

Dave Alvey Paul Moley

Plan of Presentation

Introduction Dave

Design of Trial Paul

Tables Dave

Results and Conclusion Paul

Introduction

• A study to estimate the cost-effectiveness of three strategies to increase breast cancer screening– Reminder postcard– Reminder telephone call– Motivational telephone call

• Published in Effective Clinical Practice (2000)– Authors: Fishman, Taplin, Meyer, Barlow

• Based on trial conducted by Taplin et al (2000)

Why Cost Effectiveness Analysis?

• Cost effectiveness analysis (CEA) more appropriate than cost benefit analysis in many health care applications

• Screening women aged 50-69 for breast cancer is known to reduce cancer mortality by 25%-30% within 5 or 6 years

• Benefits so great: no choice but to use screening• Cost effectiveness of screening, including promotion

method, is the appropriate economic analysis

Market Context

• Health care market prompts plans to improve delivery of preventive services like mammographic screening

• Health insurance purchasers prefer insurance plans conforming to standards like HEDIS (Health

Plan Employer Data Information Set)• HEDIS includes mammography participation• Health Plans, increasingly, will need to provide

screening

Research Context

• Most cost analyses have focused on value of mammographic screening

• Research consensus: – screening of women aged 50-69 reduces mortality rate

• Hurley et al, 1992, analyzed the costs of screening and concluded that:– personal promotion strategies (personalized letters) are

more cost effective than public promotion strategies (newspaper ads or community campaigns)

The Data Source

• Data based on a trial at Group Health Cooperative (GHC) of Puget Sound, western Washington State

• GHC is a health maintenance organization – an organization that provides managed care for health insurance

contracts as a liaison with health care providers (hospitals, doctors, etc)

• GHC wished to improve participation in their breast cancer screening programme

• GHC has 500,000 enrollees• Socioeconomic status of enrollees similar to that of

the communities in which it provides care

Design of Trial (part 1)11,570 women due for a mammogram

6,147 women approached for recruitment

5,062 eligible women 50-79 of age due for a mammogram

703 already scheduled; 382 otherwise ineligible

3,743 women 50-79 years of aged completed survey

Mailed recommendation to schedule mammography

Mammography scheduled within 2 months?

Trial Design (pt 2)

Mammography scheduled within 2 months?

Withdrew before random

assignment(n = 13)

NoRandomly assigned to

intervention group(n = 1,765)

Yes(N = 1,965)

Postcard reminder(n = 590

Reminder call(n -= 585)

Motivational call(n = 590)

The Three Intervention Groups

• Postcard Reminder (590)– screening important, please make an appointment

• Reminder Call (585)– same message by phone

• Motivational Call (590)– engaged woman in discussion on merits of

screening

Characteristics of Participantsin the Randomized Trial

Variable Promotional StrategyReminder Postcard

(n = 590)Reminder Call

(n = 585)Motivational Call

(n = 590)

Mean age ± SD, yr 61.7 ± 9.3 62.2 ± 8.8 61.9 ± 9.1

Ethnicity

White 90% 89% 88%

Hispanic <1% 1% 1%

Black 4% 4% 4%

Asian or Pacific Islander 3% 4% 4%

Other 3% 2% 3%

Participants who had previous mammogram 72% 73% 72%

Chart of Effectiveness of Interventions

Costs Table

Calculation of Cost EffectivenessVariable Cost

Marginal Cost Effectiveness

Marginal Effectiveness

Marginal Cost Effectiveness

All women Initial recommendation letter $2.07 0.1805 Reminder postcard $6.02 $3.95 0.361 0.1805 $21.88Reminder call $21.22 $15.20 0.526 0.165 $92.12Motivation call $25.99 $4.77 0.503 -0.023 Dominated Women with previous mammography Initial recommendation letter $2.07 0.2275 Reminder postcard $6.02 $3.95 0.455 0.2275 $17.36Reminder call $21.24 $15.22 0.625 0.17 $89.53Motivation call $25.76 $4.52 0.604 -0.021 Dominated Women without previous mammography Initial recommendation letter $2.07 0.0565 Reminder postcard $6.02 $3.95 0.113 0.0565 $69.91Reminder call $21.19 $15.17 0.265 0.152 $99.80Motivation call $26.51 $5.32 0.24 -0.025 Dominated

ICER compared toMarginal Cost Effectiveness

For comparing two alternative treatments, the incremental cost effectiveness ratio (ICER) is usedICER = (Cost A – Cost B) / (Effect A – Effect B)Generally, B is the status quoICER below a certain threshold is considered cost-effectiveICER below zero indicates an intervention that is cost-effective and cost saving

Marginal Cost Effectiveness - a Similar Ratio

Marginal Cost (MC) of Postcard = Cost of initial letter and postcard – Cost of Initial Letter

Marginal Effectiveness of Postcard = Effectiveness of Postcard – Effectiveness of Letter

Marginal Cost Effectiveness of Postcard = MC of Postcard / Marginal Effectiveness of Postcard

Cost Accounting IssueThe unit cost of each strategy per participant is:

Initial Letter ReminderPostcard

Reminder Call Motivational Call

$2.07 $6.02 $21.22 $25.99

The cost per woman screened is a better measure of cost because the strategies had varying degrees of success.This is calculated by dividing the unit cost by the effectiveness rate of each strategy.

Initial Letter ReminderPostcard

Reminder Call Motivational Call

$2.07 / .1805 $6.02 / .361 $21.22 / .526 $25.99 / .503

= $11 = $17 = $40 = $52

Sensitivity Analysis Graphic

Discussion of Results

• Randomized trial of women aged 50-79 yrs who had failed to schedule a mammogram following a recommendation letter

• Cost per women screened was:– $17 for reminder card– $40 for reminder call– $52 for motivational call

• Marginal cost effectiveness was:– $22 for reminder card– $92 for reminder call– motivational call was dominated

Discussion of Results Cont’d

• Motivational call not cost effective– higher cost than reminder call– less effective than reminder call

• Reminder call more effective than postcard• But analysis showed reminder call’s greater

unit cost outweighed its greater effectiveness• Therefore reminder postcard is most cost

effective option

Discussion of Results Cont’d

• Cost effectiveness ratios were influenced by whether women previously had mammography

• the advantage of the postcard over the call decreased among women who had never had mammography

• Health plans may place a high enough value on the increased participation to warrant the additional expense

Concluding Qualifications

• Results limited by relying on a trial at a single health plan

• Promotional strategies may have different effects in settings with different experiences with breast cancer screening

• Analysis did not address whether the value of postcard strategy deteriorates over time– Subject for future research?