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The Mortality of China’s Oldest Old: Comparisons from the Healthy Longevity Survey (HLS) and the 2000 Census

Daniel Goodkind International Programs Center

This report is released to inform interested parties of ongoing research and to encourage discussion. The views expressed are those of the author and not necessarily those of the U.S. Census Bureau. The use of data not generated by the U.S. Census Bureau precludes performing the same statistical reviews on those data which the U.S. Census Bureau does on its own data.

Helping You Make Informed Decisions

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Goal: Compare mortality rates derived from the HLS and the 2000 Census

1. 1. Which source would we expect to have more complete reporting of deaths?

2. 2. How similar are these rates?

2. 3. What are the reasons for any differences?

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U.S. Census Bureau estimates and projections of country populations online at:

w w w . c e n s u s . g o v Look under “I” for “International DataBase”(IDB)

For China, we use: • 1990 Census as Base Year.• Mortality, fertility, net migration, etc. from

census & other sources.• Adjustments to above based on

comparisons with 2000 census.• Always looking to confirm above “absolutes”.

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Completeness of Death Reporting: Advantages of HLS over 2000 Census

Census mortality may be undercounted:

*Census not focused on health/mortality *Questions ask of deaths to all household

members over the past year- not focused on individuals- ambiguity about belonging to this HH?

=>Respondents may forget/not report deaths

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Completeness of Death Reporting: Advantages of HLS over 2000 Census

Example of census mortality underreporting:

*Hill and Banister (2004) – deaths of all adults in 2000 Census

underreported by:

11% for males

18% for females

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Completeness of Death Reporting: Advantages of HLS over 2000 Census

Advantages of the HLS:*Focuses on specific elder

*Focuses on health and longevity of that elder

*Longitudinal design, waves 2.3 years apart

=>Deaths could not be “forgotten” by follow-up respondents in the HLS

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Female Central Death Rates in 2000 Census for All China, 22 Provinces Included in Healthy Longevity Survey (HLS),

and 9 Provinces Not in HLS

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

80-84 85-89 90-94 95-99 100+

Age

nMx

2000 Census - 22 provinces in HLS

2000 Census - All China

2000 Census - 9 provinces not in HLS

Source: Population Census Office (2002)

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Male Central Death Rates in 2000 Census for All China, 22 Provinces Included in Healthy Longevity Survey (HLS),

and 9 Provinces Not in HLS

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

80-84 85-89 90-94 95-99 100+

Age

nMx

2000 Census - 22 provinces in HLS2000 Census - All China2000 Census - 9 provinces not in HLS

Source: Population Census Office (2002).

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Age at Initial Interview in Healthy Longevity Survey (HLS) (among those in the "risk set" of dying; n=8182, see text)

0100200300400500600700

77 82 87 92 97 102 107 112

Age at initial interview

Num

ber

Male

Female

Source: Healthy Longevity Survey.

Age 100

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Risk Sets Used to Compare Mortality (Central Death Rates) in 2000 Census & HLS

|---------x-------|| 2000 Census 11//’99 11/’00

2nd wave …. |--------x--------||… HLS Risk Set Avrg.7/’99 Avrg. 7/’00 Desired

1st wave

…||--------x--------|--------x--------|… HLS Risk Set Avrg. 5/’98

Avrg.5/’00 Used

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Initial Sample Size and Sequential Loss in Our Analysis due to:

Sample SizeRemaining Loss

9093 Initial Round of Respondents 8199 894 Loss to Follow Up 8182 17 Death Year not Stated 6674 1508 Deaths During 1st Year 5010 633 Censored Cases Removed 4377 1664 Deaths During 2nd Year

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Female Central Death Rates in China by Single Years of Age: Healthy Longevity Survey (HLS) versus 2000 Census

0

50

100

150

200

250

300

350

400

450

80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

Age

nM

x

Census 2000 - nMx 22 provincesHLS - nMx 1st & 2nd year after 1st interviewHLS - (censored cases in 2nd year removed)

Source: Healthy Longevity Survey and Population Census Office (2002).

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Male Central Death Rates by Single Years of Age: Healthy Longevity Survey (HLS) versus 2000 Census

0

50

100

150

200

250

300

350

400

450

80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99Age

nM

x

2000 Census - nMx 22 provincesHLS - nMx 1st & 2nd year after 1st interviewHLS - (censored cases in 2nd year removed

Source: Healthy Longevity Survey and Population Census Office (2002).

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HLS death rates 20-25 percent lower compared to census. Why?

* About half of enumerated areas not randomly chosen* 80- and 90-enarians were matched to 100-enarians. Selected for better health? * Note – 20-25% shortfall in HLS s based on unadjusted census mortality* Comparison – China’s census rural/urban difference in adult nMx only 15%

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Female Central Death Rates in China by Single Years of Age: Healthy Longevity Survey (HLS) versus 2000 Census

0

50

100

150

200

250

300

350

400

80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

Age

nMx

Census 2000 - nMx 22 provincesHLS - nMx 2nd year after 1st interviewHLS - nMx 1st & 2nd year after 1st interviewHLS - nMx 1st year after 1st interview

Source: Healthy Longevity Survey and Population Census Office (2002).

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Male Central Death Rates by Single Years of Age: Healthy Longevity Survey (HLS) versus 2000 Census

0

50

100

150

200

250

300

350

400

450

500

80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

Age

nMx

2000 Census - nMx 22 provincesHLS - nMx 2nd year after 1st interviewHLS - nMx 1st & 2nd year after 1st interviewHLS - nMx 1st year after 1st interview

Source: Healthy Longevity Survey and Population Census Office (2002).

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Percent All Elders Who Died in HLS by Calendar Month of Surveyed Interval*

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

Month

Perc

ent

|1999 ->

|2000 ->1998 ->

*Central death rates per month

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Percent of Elders in Healthy Longevity Survey (HLS) Dying During Calendar Months of the Surveyed Interval*

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

4.0%

Per

cent

June 1999 - May 2000June 1998 - May 1999

Source: Healty Longevity Survey (central death rates per calendar month; not scaled to offset progressive aging of sample) .

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Why higher mortality in 2nd year after initial interview?

*Mortality truly rose over time?

*Drop-out Bias: Drop-outs were unhealthy and died early?

*Respondents “forgot” about deaths occurring further back in time?

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Health of Respondents at Initial Interview: Respondents Followed-Up Versus Those Not

Initial Health Followed Lost toas Rated by Interviewer Up in 2000 Follow Up

Surprisingly Healthy 40% 45%Relatively Healthy 44% 41%Moderately Ill 11% 10%Very Ill 4% 4%Missing 1% 1%

Total 100% 100%N 8199 894

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Another Hypothesis Involving Recall -

Telescoping – Misrecall bias causing respondents to shift forward the date of events

“It seemed like only yesterday that ..”

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Implications of Telescoping

*At least 10 percent of deaths in 1st year after initial interview were misreported in 2nd year

*Evidence of telescoping in the 3rd wave? (2002)

*Could telescoping also bias census results upward?

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Summary

We expected mortality rates from HLS to be higher than from 2000 Census

We found the opposite

Reasons – *Selection issues in HLS *Possible telescoping in 2000 Census

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Do these findings affect all conclusions from HLS?

Probably not - Conclusions drawn about relative differences in the HLS (e.g. sex, education, ADLs and mortality. etc.) may well be valid.

Yet absolute levels of mortality among China elders still somewhat uncertain.

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Thank You!

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