December 2006

What is the best method to immunize individuals? Vaccinations are typically delivered via scheduled or walk-in visits. Mass vaccinations, however, may offer a more efficient means to vaccinate large populations. The mass vaccination locations can take place at schools, convention centers, fair grounds, churches, parking lots or other places (see Arkansas’ Mass Flu Vaccine locations as an example).

Authors John Fontanesi, Linda Hill and colleagues take a more in depth look at this issue in their 2006 paper. The researchers found that while only 59% of individuals who saw a physician for a well visit received a flu shot, 99% of those who went to a mass immunization clinic received the flu shot. The cost to administer the vaccines at the two sites were remarkably similar (see below).

Direct Unit Costs

Thus, if we measure productivity as the cost for each person vaccinated, we see that mass clinics are about twice as productive. Regular office visits, however, are able to detect other health problems, whereas mass clinics only administer influenza vaccinations. Information gathering at mass vaccination clinics is minimal. The authors define efficiency as the quality of the visit divided by the cost of the visit. On this scale, the the study finds that office visits dominate mass vaccination clinics since they offer more patient education and better documentation of the encounter (see below). The authors conclude that “balancing critical resources…with the need to vaccinate as many at-risk patients…may be best accomplished by tightly integrating routine scheduled mass vaccination clinics with ambulatory care centers…”

Productivity (The lower score, the greater the productivity)

Efficiency (The higher the score, the greater the efficiency)

A second paper by Fontanesi and colleagues published in 2004 uses critical path analysis to analyze the rate of influenza immunization at 1) scheduled visits, 2) walk-in visits, 3) scheduled shot only visits, and 4) walk-in shot only. They find vaccination rates similar to the 2006 paper listed above. Immunization rates are 58%, 45%, 100%, and 98% respectively. The main indicators which contributed to a vaccination occurring were 1) the patient and provider discuss immunization, 2) the ratio of the number of providers to the number of registration staff, 3) the ratio of the number of providers to the number of exam rooms, and 4) the patient was asked about the examination in the exam room or before the exam. The authors wisely conclude the following:

“Critical path analysis of vaccination activities occurring during routine scheduled health encounters suggests that this is a complex task and should not simply be seen as an incremental activity added to the general health encounter. Critical path analysis also suggests that provider-patient discussion is more productively viewed as the culmination rather than the beginning of the vaccination process.”

• Fontanesi; Hill; Olson; Bennett; Kopald; (2006) “Mass vaccination clinics versus appointments.” Medical Practice Management, vol March/April, pp. 1-7.
• Fontanesi, J., A. M. Shefer, D. B. Fishbein, N. M. Bennett, M. De Guire, D. Kopald, K. Holcomb, D. W. Stryker and M. S. Coleman. “Operational Conditions Affecting the Vaccination of Older Adults.” American Journal of Preventive Medicine, 2004, 26 (4), pp. 265-270.

Yesterday we examined the cost effectiveness of the influenza vaccine in children. Today I will look at two papers which focus on the same question using children as the sub-population of interest. Estimated influenza infection rate among young healthy children is between 35% and 50% each year.

Cohen and Nettleman (2000) look at preschool children and create a cost-benefit scenario under a flexible and fixed (i.e.: 8am – 5pm) schedules. The net cost savings for the vaccination is calculated as below.

The authors find that direct costs of administering the vaccination can be as little as $4 in an HMO, and up to $10 in an outpatient stand-alone practice. Cost savings from the vaccination results from fewer pediatric office visits (estimated to cost $51/visit) and fewer ER visits (estimated at $124.42/visit) as well as fewer antibiotics used and fewer hospitalizations. Indirect costs included the parental time spent in the doctor’s office with their child as well as time absent from work from having to take care of a sick child.

This analysis shows that flexible vaccination is far superior to fixed schedule vaccination. The problem with this is that it is likely that health care providers would need to be compensated more to work a flexible schedule which may decrease the cost savings. Also, vaccination costs do not count physician rent, utilities, staffing, chart maintenance, etc. which go into the cost of a physician visit.

A second, more reliable study is preformed by Luce, et al. (2001). This study employs data from a multicenter, prospective, randomized, double-blind, placebo controlled efficiency trial during two flu seasons (fall 1996 through spring 1998). The vaccine studied was the live, attenuated, trivalent, intranasal influenza vaccine (not the more commonly used intramuscular shot). It was found that vaccinated children have 1.2 fewer influenza related illness (ILI) fever days/child than unvaccinated children. The costs of the vaccine are analyzed are as follows:

For the direct costs, the authors take into account the vaccine cost, time to administer the vaccine, and medication use from adverse affects of the vaccine. To measure the health care resources used to treat ILI, the authors look at expected costs from hospitalization, health care provider visits (ER or physician), laboratory and diagnostic tests and procedures, antibiotics and other prescription or over-the-counter medications.

Direct non-medical costs and lost productivity costs are measure using transportation costs (e.g.: vehicle mileage and parking costs) and caregivers’ time costs respectively. Most of the cost data is culled from other papers or NAMCS and NHAMCS data. The authors find that from society’s point of view, a $28 intranasal vaccination was worth the cost. From an individual’s point of view, an intranasal vaccination costing less than $5 was worth the cost. The individual’s break even value is lower than society’s since the individual does not take into account the externality that if they are vaccinated, it is less likely that someone else becomes infected with influenza.

• Cohen; Nettleman (2000) “Economic Impact of Influenza Vaccination in Preschool Children” Pediatrics, vol 106, no. 5, pp. 973-976.
• Luce; Zangwill; Palmer; Mendelman; Yan; Wolff; Marcy; Iacuzio; Belshe; (2001) “Cost-effectiveness analysis of an intranasal influenza vaccine for the prevention of influenza in healthy children.” Pediatrics, vol. 108, no. 2, E24.

How does one measure the cost effectiveness of flu vaccination? Today we will examine a paper which attempts to do just that.

Nichol, et al. (2003) preforms a cost-benefit analysis of live attenuated influenza vaccination (LAIV) for healthy, working adults. This type of vaccination is administered through a nasal spray than through an intramuscular shot. The authors attempted to answer this question using a multi-center, randomized, double blind placebo controlled trial. They found that adult influenza vaccinations decreased the number of work days missed by 18%, decreased the number of less effective work days by 18% and decreased the number of provider visits by 13%. This amounts to a large benefit to society, but one must also estimate the costs of vaccination in order to have an accurate cost-benefit analysis. Nichol and colleagues estimate the costs as follows:

Provider visit costs is estimated separately for influenza-like illness (ILI) and upper respiratory tract illness. Costs include not only physician time, but also the average number of tests and procedures ordered and medications prescribed (e.g.: antibiotics, Rx and over the counter meds) and are estimated using NAMCS data. The authors find that the break even cost of flu vaccinations for healthy adults is $43.07. Monte Carlo simulation is then used to prove their results more robust.

The study does have some problems. The authors do not include overhead costs in their estimate of physician visits. Secondly, no justification is found for the distributional assumptions of the Monte Carlo simulations. Most distributions are triangular between the min and the max.

• Nichol; Mallon; Mendelman; (2003) “Cost benefit of influenza vaccination in healthy, working adults: An economic analysis based on the results of a clinical trial of trivalent live attenuated influenza virus vaccine” Vaccine, vol 21, pp. 2207-2217.

According to Thompson, et al. (2003), approximately 51,000 people per year died annually due to influenza related diseases between 1990 and 1999. Mortality rates are appreciably higher for those over 65 years of age.

In order to reduce mortality and morbidity from influenza in the U.S., the CDC’s Advisory Committee on Immunization Practices (ACIP) released its “Prevention and Control of Influenza” guide this summer. The report documents important information regarding influenza and gives recommendations to patients and providers regarding when/for whom/in what manner influenza vaccinations should be administered.

According to this paper, influenza is divided into two types: influenza A and influenza B. Influenza A is further divided into two subgroups: hemagglutinin and neuraminidase. Influenza represents a unique family of viruses since antibodies developed against one strain of influenza offer little or no protection from other strains. There are also two types of vaccines. The live attenuated influenza vaccine (LAIV) uses live but weakened influenza virus. LAIV is administered through a nasal spray. The second, more traditional vaccine is the inactivated vaccine which is administered through an intramuscular injection and uses killed viruses. While the LAIV is often less unpleasant for the patient, it is usually more costly than the inactivated vaccine.

Hospitalization Rates
A variety of studies have found the following hospitalization rates which occur as a result of influenza. Below are a summary of a few studies which analyze the American population.

New Recommendations
The influenza vaccine is now recommended for a wide range of people (see “Persons for whom annual vaccination is recommended” below). Three important changes in ACIP’s vaccination policies for 2006 are:

• Children under 6 years and parents of children under 6 should receive an annual flu vaccine.

• Children under 9 years of age who have never been vaccinated should receive 2 doses of the vaccine.

• Continued offering of the influenza vaccine even after influenza activity has been documented in a community.

Persons for whom annual vaccination is recommended

• Children aged 6–59 months;

• Women who will be pregnant during the influenza season;

• Persons aged >50 years;

• Children and adolescents (aged 6 months–18 years) who are receiving long-term aspirin therapy and, therefore, might be at risk for experiencing Reye syndrome after
  influenza infection;

• Adults and children who have chronic disorders of the pulmonary or cardiovascular systems, including asthma (hypertension is not considered a high-risk condition);

• Adults and children who have required regular medical follow-up or hospitalization during the preceding year because of chronic metabolic diseases (including diabetes
  mellitus), renal dysfunction, hemoglobinopathies, or immunodeficiency (including immunodeficiency caused by medications or by human immunodeficiency virus);

• Adults and children who have any condition (e.g., cognitive dysfunction, spinal cord injuries, seizure disorders, or other neuromuscular disorders) that can compromise respiratory function or the handling of respiratory secretions, or that can increase the risk for aspiration;

• Residents of nursing homes and other chronic-care facilities that house persons of any age who have chronic medical conditions;

• Persons who live with or care for persons at high risk for influenza-related complications, including healthy household contacts and caregivers of children aged 0–59 months; and
• Health-care workers.

The important changes

• Thompson,; Shay; Weintraub; (2003) “Mortality associated with influenza and respiratory syncytial virus in the United States.” JAMA, vol 289, pp. 179-186.

• “Prevention and Control of Influenza: Recommendations of the Advisory Committee on Immunization Practices (ACIP)” MMWR: Morbidity and Mortality Weekly Report; CDC. July 28, 2006, Vol. 55, No. RR-10, pp. 1-42.

Which treatment is more effective: placebo one or placebo two? This is the test researchers Ted Kaptchuk and colleagues investigated in their study published in the British Medical Journal and summarized in an April 2006 issue of Discover (“Placebo vs. Placebo“). Kaptchuk looked at 266 volunteers with chronic arm pain and randomly assigned each of them to either receive a sugar pill or be subjected to pretend acupuncture.

Both groups experienced side effects to the placebos:

“25 percent of the acupuncture group experienced side effects from the nonexistent needle pricks, including 19 people who felt pain and 4 whose skin became red or swollen. 31 percent of the pill group experienced side effects from the make-believe drug, including dizziness, restlessness, rashes, headaches, nausea, and 4 cases of nightmares. Dry mouth and fatigue were the most common side effects, and 3 subjects withdrew from the study after reducing the dosage failed to control their symptoms. The reported side effects exactly matched those described by the doctors at the beginning of the study.”

After ten weeks, individuals receiving the fake acupuncture reported a larger reduction in pain than those taking the sugar pill. Kaptchuk has a logical explanation for this.

“Kaptchuk says that the rituals of medicine explain the difference: Performing acupuncture is more elaborate than prescribing medicine. Other rituals that may make patients feel better include ‘white coats, and stethoscopes that you don’t necessarily use, pictures on the wall, the way you reassure a patient, and the secretaries that sign you in.’ Careful manipulation of such rituals could make all types of treatment more effective, Kaptchuk suggests.“