Deborah Wingard, W. Susan Cheng, Donna Kritz-Silverstein, Elizabeth Barrett-Connor Sensitivity and Specificity of Death Certificates for Diabetes: As Good as it Gets? Insulin Hexamer

Introduction Diabetes sixth major cause of death in US Among diabetic population, diabetes listed 20%-50% anywhere on death certificates Mortality data used for policy decisions Disease reporting Burden of disease Funding

Introduction Death Certificates for Disease Reporting Death Certificates for Disease Reporting No standard form No standard form No standard training No standard training Inadequate fields Inadequate fields Not regular physician Not regular physician

Purpose Examine change in accurate reporting of diabetes on death certificate Potential factors improving reporting: Sex Age, year, place, & cause of death Diabetes medication use

Methods Rancho Bernardo cohort Age 30+ at enrollment ( ) Mortality data through 2003 follow-up: 1-30 years mean = yrs Death certificates for 3209 decedents

Methods Diagnosed Diabetes Periodic clinic visits , , , Blood work & self-report Mailed questionnaires 1982, 1988, 1993, 1996, 1998 Diabetes Listed on Death Certificate Anywhere Cause of Death

Death Certificates Underlying cause of death Consequence leading to death Significant conditions.

3209 w/Death Certificate And ICD9 Codes Diabetes (n=322) No Diabetes (n=2887) Diabetes (n=112) No Diabetes (n=210) Diabetes (n=56) No Diabetes (n=2831) Diabetes Listed On Death Certificates Diabetes Reported During Study

Methods Sensitivity and specificity Unadjusted and Stratified Sex Age at death Year of death Place of death Cause of death Diabetes medication use

Accuracy of Reporting: Sensitivity and Specificity Diabetes on Death Certificate YesNo Diabetes Status Ever Reported (Yes) A B A+B Never Reported (No)C DC+D Sensitivity:A/(A+B) Specificity:D/(C+D)

Logistic Regression Sample: 378 diabetic decedents Outcome: Death certificate reporting diabetes Predictors of Better Reporting: Sex Sex Age, year, place, cause of death Age, year, place, cause of death Diabetes medication use Diabetes medication use

3209 w/Death Certificate And ICD9 Codes Diabetes (n=322) No Diabetes (n=2887) Diabetes (n=112) No Diabetes (n=210) Diabetes (n=56) No Diabetes (n=2831) Diabetes Listed On Death Certificates Diabetes Reported During Study

Descriptives of Decedents Mean age (yrs) At Visit 1: 65 At Death: 82 Sex (%) Men: 51 Women: 49

Descriptives of Decedents Place of Death (%) Hospital: 67 Home: 22 Other: 11 Year of Death (%) : : : 37 Cause of Death (%) CVD: 41 Diabetes: 1 Cancer: 23 Other: 35

Descriptives of Decedents DiabetesNo Diabetes Age at Enrollment (yrs): Men (%): CVD deaths (%): No difference: age at death, place & year of death

Results: Accuracy of Reporting 322 decedents with reported diabetes 168 listed diabetes anywhere on death certificates 56 did not report diabetes Sensitivity of diabetes reporting Anywhere: 34.7% Cause of Death: 6.2% Specificity of diabetes reporting Anywhere: 98.1% Cause of Death: 99.8%

Stratified Sensitivity Characteristic NSensitivity (%) Sex Men Women Age at Death (yrs) <76 (ref) Year of Death (ref)

Stratified Sensitivity (cont) Characteristic NSensitivity(%) Cause of Death All Other CVD Place of Death Other (ref) Hospital Home Diagnosis MD only MD + medication use 18349

Summary of Results Higher sensitivity for diabetes reporting: Deaths in hospitals, home CVD as underlying cause Diabetes medication use Sensitivity did not vary by: Sex Age of death Year of death

Logistic Regression Among Diabetic Decedents (n=378) CharacteristicOR95%CI Age1.00.9, 1.0 Men vs. women1.51.0, 2.2 Year of Death1.00.9, 1.0

Logistic Regression Among Diabetic Decedents (n=378) CharacteristicOR95%CI Cause of Death CVD v. all other1.40.9, 2.2 Place of Death Hospital v. other1.00.5, 2.2 Home v. other1.00.6, 1.9 Diagnosis Db med. use v. Dx only4.82.8, 8.1

CVD v. all other cause of death by decade of death Sensitivity (%)

Summary: US Population-Based Author (year) N Years Ages Sensitivity (%) Minnesota Palumbo (1976) Ochi (1985) Spratka (1993)  =74 54 North Dakota Brousseau (1987)  =77 45 Washington Anderson (1993)  =69 41 Rancho Bernardo Present study  =82 35  mean

Summary: US National Author (year) N Years Ages Sensitivity (%) Diabetic Eye Disease MMWR (1991) Mortality Follow-Back Bild (1992) NHANES Gu (1998) 14, (Men) 47 (Women) Will (2001) 16, ,

Summary: Studies Abroad Author (year) N Years Ages Sensitivity (%) Scotland Waugh (1985) Jamaica Alleyene (1989) All 67 Portugal Coeli (2002)

Strengths & Limitations Limitations Generalizability White, middle class, good access to medical care Results similar to other US based studiesStrengths Direct access to individuals Direct access to individuals Lengthy follow-up period Lengthy follow-up period Recent data Recent data

Conclusions No overall improvement in diabetes reporting on death certificates Better reporting observed in recent years ( ) for CVD listed as cause of death Persistent under-reporting of diabetes on death certificates leads to an underestimate of the burden of disease in the population

Questions? Rancho Bernardo, CA

Table 1: Descriptives of Sample

Descriptives of Decedents Place of Death (%) Hospital: 67 Home: 22 Other: 11 Year of Death (%) : : : 37 Mean age (yrs) At Visit 1: 65 At Death: 82 Sex (%) Men: 51 Women: 49 Cause of Death (%) CVD: 41 Diabetes: 1 Cancer: 23 Other: 35

Logistic Regression Among Diabetic Decedents (n=378) CharacteristicOR95%CI Age1.00.9, 1.0 Men vs. women1.51.0, 2.2 Year of Death1.00.9, 1.0 Cause of Death CVD v. all other1.40.9, 2.2 Place of Death Hospital v. other1.00.5, 2.2 Home v. other1.00.6, 1.9 Diagnosis Db med. use v. Dx only4.82.8, 8.1

Summary: US Based Studies Author (year) N Years AgesSensitivity (%) Palumbo (1976) Ochi (1985) Spratka (1993)  =74 54 Brousseau (1987)  =77 45 Anderson (1993)  =69 41 National Studies MMWR (1991) Bild (1992) Gu (1998) 14, (Men) 47 (Women) Will (2001) 16, ,  mean

US Based Studies (Sensitivity %) Local Studies Minnesota Prospective (32%) Pop based (38%) Pop based (54%) North Dakota Pop based (45%) Washington Pop based (41%) National Studies Diabetic Eye Disease (48%) Mortality Follow-back (38%) NHANES 36% Men, 47% Women