Cover Image

HARDBACK
$52.95



View/Hide Left Panel

APPENDIX 17
Neisseria gonorrhea

DISEASE BURDEN

Epidemiology

For the purposes of the calculations in this report, the committee estimated that there are 1 million new cases of gonorrhea infection each year in the United States. Slightly more than half of these occur in males. It was assumed that 90% of cases occur in people between 15 and 34 years of age. Mortality was presumed to be minimal; 5 deaths were included for women per year (consequences of serious sequelae, for example). See Table A17–1 for a summary of the age distribution of gonorrhea infections.

Disease Scenarios

For the purposes of the calculation in this report, the committee assumed that 50% of cases in women are asymptomatic, but that half of those cases are detected through screening programs and receive treatment. The other 50% of cases experience mild manifestations, such as cervicitis, urethritis, or endometritis. More serious acute health consequences associated with gonorrhea infections in women include pelvic inflammatory disease (PID), salpingitis, and perihepatitis. Consequences of PID are assumed to occur with a 5-year lag from infection and include ectopic pregnancy, chronic pelvic pain, and infertility. The health utility index and length of time spent in the health state range from .85 HUI for 7 days (cervicitis) to .46 HUI for 2 days (surgery for PID) to .6 HUI for more than 20 years (chronic pelvic pain).



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking APPENDIX 17 Neisseria gonorrhea DISEASE BURDEN Epidemiology For the purposes of the calculations in this report, the committee estimated that there are 1 million new cases of gonorrhea infection each year in the United States. Slightly more than half of these occur in males. It was assumed that 90% of cases occur in people between 15 and 34 years of age. Mortality was presumed to be minimal; 5 deaths were included for women per year (consequences of serious sequelae, for example). See Table A17–1 for a summary of the age distribution of gonorrhea infections. Disease Scenarios For the purposes of the calculation in this report, the committee assumed that 50% of cases in women are asymptomatic, but that half of those cases are detected through screening programs and receive treatment. The other 50% of cases experience mild manifestations, such as cervicitis, urethritis, or endometritis. More serious acute health consequences associated with gonorrhea infections in women include pelvic inflammatory disease (PID), salpingitis, and perihepatitis. Consequences of PID are assumed to occur with a 5-year lag from infection and include ectopic pregnancy, chronic pelvic pain, and infertility. The health utility index and length of time spent in the health state range from .85 HUI for 7 days (cervicitis) to .46 HUI for 2 days (surgery for PID) to .6 HUI for more than 20 years (chronic pelvic pain).

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking Table A17–1 Incidence of N.gonorrhea Infection in Women and Men Age Groups Female Population Incidence Rates (per 100,000) % Distribution of Cases Cases <1 1,933,000 0.00 0.0000 0 1–4 7,905,000 29.10 0.0050 2,300 5–14 18,554,000 111.57 0.0450 20,700 15–24 17,747,000 1,555.19 0.6000 276,000 25–34 20,835,000 662.35 0.3000 138,000 35–44 21,238,000 75.81 0.0350 16,100 45–54 15,447,000 29.78 0.0100 4,600 55–64 11,140,000 20.65 0.0050 2,300 65–74 10,544,000 0.00 0.0000 0 75–84 6,814,000 0.00 0.0000 0 85+ 2,593,000 0.00 0.0000 0 Total 134,750,000 341.37 1.0000 460,000 Age Groups Male Population Incidence Rates (per 100,000) % Distribution of Cases Cases <1 2,030,000 0.00 0.0000 0 1–4 8,314,000 32.48 0.0050 2,700 5–14 19,502,000 124.60 0.0450 24,300 15–24 18,516,000 1,749.84 0.6000 324,000 25–34 20,835,000 777.54 0.3000 162,000 35–44 20,911,000 90.38 0.0350 18,900 45–54 14,777,000 36.54 0.0100 5,400 55–64 10,101,000 26.73 0.0050 2,700 65–74 8,420,000 0.00 0.0000 0 75–84 4,274,000 0.00 0.0000 0 85+ 1,005,000 0.00 0.0000 0 Total 128,685,000 419.63 1.0000 540,000 For the purposes of the calculations in this report, the committee assumed that 15% of cases in men are asymptomatic and untreated. The overwhelming utility index and length of time spent in the health state range from .85 HUI for 7 days (cervicitis) to .46 HUI for 2 days (surgery for PID) to .6 HUI for more than 20 years (chronic pelvic pain). For the purposes of the calculations in this report, the committee assumed that 15% of cases in men are asymptomatic and untreated. The overwhelming proportion of symptomatic cases involve urethritis, which was assumed to be associated with an HUI of .84 and 7 days duration. A small percentage of men infected with gonorrhea experience epididymitis. The HUI and length of time spent in the health state for these manifestations range from .84 HUI for 7 days (urethritis) to .3 HUI for 3 days (hospitalization for epididymitis). A small fraction of both men and women infected with gonorrhea experience disseminated infections. Hospitalization for these patients is associated with an HUI of .52 for 4 days; outpatient treatment is associated with a week of a higher HUI state. See Table A17–2 for a summary of the disease states associated with gonorrhea infections.

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking Table A17–2 Disease Scenarios for N.Gonorrhea Infection in Women and Men   % of Cases Committee HUI Values Duration (years) WOMEN   Total Cases 460,000   Asymptomatic 50.0% 1.00   untreated 25.0%   treated (detected in screening, etc.) 25.0% Mild (cervicitis, urethritis, endometritis, bartholinitis) 50.0%   outpatient   0.85 0.0192 (7 days) Serious (PID, salpingitis, perihepatitis) —outpatient only 10.0% 0.63 0.0274 (10 days) Serious (PID, salpingitis, perihepatitis) —inpatient   inpatient—no surgery 7.5% 0.57 0.0110 (4 days) inpatient with surgery 2.5% 0.46 0.0055 (2 days) outpatient after inpatient 10.0% 0.83 0.0274 (10 days) Serious (PID, etc.) 0.8%   inpatient with bilateral salpingo-oophorectomy   0.40 0.0027 (1 day) outpatient after inpatient   0.76 0.0274 (10 days) infertility   0.82 23.6523 (remaining lifetime at onset) ALL PID sequelae: 5-year lag from infection Ectopic Pregnancy—Outpatient only 3.3% 0.58 0.0767 (4 weeks) Ectopic Pregnancy—Inpatient 3.3%   inpatient   0.23 0.0082 (3 days) outpatient after inpatient   0.66 0.0767 (4 weeks) Chronic pelvic pain 6.6% 0.60 22.7313 (remaining lifetime at onset+5 years) discounted quality adjusted life expectancy at age 28.7 Infertility 4.0% 0.82 22.7313 (remaining lifetime at onset+5 years); discounted quality adjusted life expectancy at age 28.7 Disseminated gonococcal infections (bacteremia, arthritis, etc.) —outpatient only 0.5% 0.60 0.0219 (8 days)

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking   % of Cases Committee HUI Values Duration (years) Disseminated gonococcal infections (bacteremia, arthritis, etc.) —inpatient 0.5%   inpatient   0.52 0.0110 (4 days) outpatient after inpatient   0.78 0.0192 (7 days) MEN   Total cases 540,000   Asymptomatic 15.0% 1.00   Urethritis 84.0% 0.84 0.0192 (7 days) Epididymitis—outpatient 0.9% 0.46 0.0192 (7 days) Epididymitis—inpatient 0.1% 0.30 0.0082 (3 days) Disseminated gonococcal infections (bacteremia, arthritis, etc.) —outpatient 0.5% 0.60 0.0219 (8 days) Disseminated gonococcal infections (bacteremia, arthritis, etc.) —inpatient 0.5%   inpatient   0.52 0.0110 (4 days) outpatient after inpatient   0.78 0.0192 (7 days) COST INCURRED BY DISEASE Table A17–3 summarizes the health care costs incurred by gonorrhea infections. For the purposes of the calculations in this report, it was assumed that for mild acute manifestations in both men and women (e.g., cervicitis and urethritis), health care costs include a limited visit with a physician and inexpensive diagnostics and medications. Disseminated gonococcal infections in both women and men were assumed to be associated with inpatient costs (hospitalization, diagnostics, specialist physicians) and outpatient costs (similar to that required for inpatient treatment but slightly fewer physician visits). Outpatient treatment in women of more serious manifestations include increased diagnostic costs above those for cervicitis. Inpatient treatment (e.g., for PID or salpingitis) includes hospitalization costs, physician services (including surgeons and anesthesiologists for those who require surgery) and diagnostics. Outpatient costs following hospitalization include follow-up care with a specialist. Half of the cases of ectopic pregnancy were assumed to be treated as inpatient and half as outpatient. Costs include hospital costs (more for inpatient), specialist physicians, surgeons and anesthesiologists, and diagnostics. A followup visit with a specialist was also included. Chronic pelvic pain was associated with numerous physician visits, diagnostics, and medication. 75% of women with chronic pelvic pain were presumed to undergo outpatient laparoscopy, and

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking Table A17–3 Health Care Costs Associated with N.gonorrhea Infection in Women and Men   % with Care Cost per Unit Units per Case Form of Treatment WOMEN   Asymptomatic   untreated   treated (detected in screening, etc.) 100% $50 1 physician a   100% $50 1 diagnostic a 100% $50 1 medication b Mild (cervicitis, urethritis, endometritis, bartholinitis)   outpatient 100% $50 1 physician a   100% $50 1 diagnostic a 100% $50 1 medication b Serious (PID, salpingitis, perihepatitis)   outpatient 100% $50 1 physician a   100% $100 1 diagnostic b 100% $100 1 medication Serious (PID, salpingitis, perihepatitis)   inpatient—no surgery 100% $4,000 1 hospitalization   100% $150 3 physician c 100% $100 1 diagnostic b Serious (PID, salpingitis, perihepatitis)   inpatient with surgery 100% $4,000 1 hospitalization   100% $150 3 physician c 100% $500 4 surgical staff 100% $100 1 diagnostic b Serious (PID, salpingitis, perihepatitis)   outpatient after inpatient 100% $100 1 physician b Serious (PID, etc.)   inpatient and outpatient 100% $1,550 1 outpatient laparoscopy ALL PID sequelae: 5-year lag from infection   Ectopic Pregnancy—Outpatient   PID sequela: 5-year lag   outpatient only 100% $1,000 1 laparoscopy   100% $500 1 surgical staff 100% $500 1 surgical staff 100% $50 1 diagnostic a 100% $100 1 physician b

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking   % with Care Cost per Unit Units per Case Form of Treatment Ectopic Pregnancy—Inpatient   PID sequela: 5-year lag   inpatient 100% $4,000 1 hospitalization   100% $150 3 physician c 100% $100 1 diagnostic b 100% $500 2 surgical staff outpatient after inpatient 100% $100 1 physician b Chronic pelvic pain   PID sequela: 5-year lag   treatment assumed to occur 5 years after onset of infection 100% $100 1 physician b duration of condition: remaining lifetime 100% $50 4 physician a   100% $50 1 medication b 100% $100 1 diagnostic b outpatient laparoscopy 75% $1,000 1 hospitalization 75% $500 1 surgical staff 75% $500 1 surgical staff lower abdominal surgery 30% $4,000 1 hospitalization 30% $500 1 surgical staff 30% $500 1 surgical staff 30% $150 3 physician c Infertility   PID sequela: 5-year lag 50% $150 6 physician c treatment assumed to occur 5 years after onset of infection   duration of condition: remaining lifetime 50% $500 1 diagnostic c   50% $250 1 procedure outpatient laparoscopy (75% of those seeking treatment) 38% $1,000 1 hospitalization 38% $500 1 surgical staff 38% $500 1 surgical staff tubal surgery (30% of those seeking treatment) 15% $1,000 1 outpatient surgery 15% $500 1 surgeon 15% $500 1 anesthesiology in vitro fertilization (12% of those seeking treatment) 6% $4,000 2 per trial

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking   % with Care Cost per Unit Units per Case Form of Treatment Disseminated gonococcal infections (bacteremia, arthritis, etc.) —outpatient     100% $100 2 physician b 100% $50 1 culture—gonorrhea 100% $50 1 medication Disseminated gonococcal infections (bacteremia, arthritis, etc.) —inpatient     100% $3,000 1 hospitalization 100% $150 3 physician c 100% $50 1 diagnostic a 100% $50 1 medication b outpatient after inpatient   $100 1 physician b MEN   Asymptomatic (untreated) Urethritis     100% $50 1 physician a 100% $50 1 diagnostic a Epididymitis   outpatient 100% $100 1 physician b   100% $50 1 physician a 100% $50 1 diagnostic a 100% $50 1 medication b Epididymitis   inpatient 100% $3,000 1 hospitalization   100% $150 3 physician c 100% $50 1 physician a 100% $50 1 medication b 50% $500 1 surgical staff 50% $500 1 surgical staff Disseminated gonococcal infections (bacteremia, arthritis, etc.) —outpatient     100% $100 2 physician b 100% $50 1 culture—gonorrhea 100% $50 1 medication Disseminated gonococcal infections (bacteremia, arthritis, etc.) —inpatient     100% $3,000 1 hospitalization 100% $150 3 physician c 100% $50 1 diagnostic a 100% $50 1 medication b outpatient after inpatient   $100 1 physician b

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking 30% were presumed to undergo abdominal surgery. For the purposes of the calculations in this report, it was assumed that half of women infertile due to gonorrhea infection seek some kind of medical care related to infertility. This includes hysterosalphoingography, outpatient laparoscopy, tubal surgery, and infertility treatment. Epididymitis in men was estimated to be treated primarily on an outpatient basis and includes costs for both limited visits and specialist physician visits, diagnostics, and medications. For the few patients who undergo surgery, costs for surgeons and anesthesiologist are included. VACCINE DEVELOPMENT The committee assumed that it will take 15 years until licensure and that $360 million needs to be invested. Table 4–1 summarizes vaccine development assumptions for all vaccines considered in this report. VACCINE PROGRAM CONSIDERATIONS Target Population For the purposes of the calculations in this report, it is assumed that the target population for this vaccine is adolescents (age 12 years). It was assumed that 50% of the target population would utilize the vaccine. Vaccine Schedule, Efficacy, and Costs For the purposes of the calculations in this report, it was estimated that this vaccine would cost $50 per dose and that administration costs would be $10 per dose. Default assumptions of a 3-dose series and 75% effectiveness were accepted. Table 4–1 summarizes vaccine program assumptions for all vaccines considered in this report. RESULTS If a vaccine program for N. gonorrhea were implemented today and the vaccine were 100% efficacious and utilized by 100% of the target population, the annualized present value of the QALYs gained would be 230,000. Using committee assumptions of less-than-ideal efficacy and utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the QALYs gained would be 47,000. Although the proportion

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking of cases are slightly higher in men than in women, the number of QALYs lost due to disease in women is over 200 fold that in men. The more severe nature of the sequelae of infection in women and the chronic nature of several of the sequelae account for this large difference. If a vaccine program for N. gonorrhea were implemented today and the vaccine was 100% efficacious and utilized by 100% of the target population, the annualized present value of the health care costs saved would be $440 million. Using committee assumptions of less-than-ideal efficacy and utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the health care costs saved would be $92.1 million. If a vaccine program for N. gonorrhea were implemented today and the vaccine was 100% efficacious and utilized by 100% of the target population, the annualized present value of the program cost would be $680 million. Using committee assumptions of less-than-ideal efficacy and utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the program cost would be $190 million. Using committee assumptions of time and costs until licensure, the fixed cost of vaccine development has been amortized and is $10.8 million for a N. gonorrhea vaccine. If a vaccine program were implemented today and the vaccine was 100% efficacious and utilized by 100% of the target population, the annualized present value of the cost per QALY gained is $1,000. Using committee assumptions of less-than-ideal utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the cost per QALY gained is $2,300. See Chapters 4 and 5 for details on the methods and assumptions used by the committee for the results reported. READING LIST Alexander LL, Treiman K, Clarke P. A National Survey of Nurse Practitioner Chlamydia Knowledge and Treatment Practices of Female Patients. Nurse Practitioner 1996; 21:48, 51–4. Gutman, LT. Gonorrhea. In: Textbook of Pediatric Infectious Diseases. RD Feigin and JD Cherry eds. Philadelphia, PA: WB Saunder Company, 1992, pp. 540–552. Handsfield HH, Sparling PF. Neisseria Gonorrhoeae. In: Principles and Practice of Infectious Diseases. GL Mandell, JE Bennett, Dolin R eds. New York, NY: Churchill Livingstone, 1995, pp. 1909–1926. Magid D, Douglas JM, Schwartz JS. Doxycycline Compared with Azithromycin for Treating Women with Genital Chlamydia Trachomatis Infections: An Incremental Cost-Effectiveness Analysis. Annals of Internal Medicine 1996; 124:389–99. U.S. Bureau of the Census. Statistical Abstract of the U.S.: 1995 (115th edition). Washington, D.C. 1995.

OCR for page 257
Vaccines for the 21st Century: A Tool for Decisionmaking This page in the original is blank.