CHAPTER 8
Hospital Utilisation Expectancies:
National and Regional Analysis
8.1
INTRODUCTION
This chapter is the first of several to provide a synthesis of mortality and morbidity patterns afforded
by the use of HUEs, as described in the previous chapter. These chapters attempt to answer some of
the questions posed in Chapter One, questions which cannot easily be answered by the analysis of
discrete factors such as morbidity or mortality alone. The results of national and regional HUE
analyses for both Māori and Total populations are presented here and include a comparison of agespecific HUEs at three time-points in the period under study together with the contribution of
expected hospital days at different ages to the total HUE(0).
Appendix tables provide the results for each region separately, along with a fuller region-by-region
profile of demographic and health indices.
8.2
LIFETIME HOSPITAL UTILISATION EXPECTANCIES AT BIRTH
(HUE (0))
National Trends
Over the period 1980-2000, the total number of days on average that New Zealanders could expect to
spend in hospital over the course of their life-time decreased by 35 percent (from 79 days to 51) for
males and by 39 percent (from 88 to 53 days) for females (see Table 8.1 and Appendix Table 8.1).
Table 8.1:
HUE at Birth (Days), Health Regions and New Zealand, By Gender,
Selected Years, 1980-2000
Region
New Zealand
Northland
Waitemata
Auckland Central
South Auckland
Waikato
BoP/Lakes
H. Bay/Tairawhiti
Taran./Wang./Man.
Wellington
Nelson-Marlb.
Central S. Island
Southern S. Island
Sources:
1980
79
87
52
57
66
88
101
92
91
77
82
82
86
1985
72
84
49
54
57
74
84
83
81
81
68
77
75
Males
1990 1995
62
54
64
46
48
46
49
50
53
51
61
51
76
58
76
64
70
59
62
54
54
45
66
53
70
61
2000
51
48
49
54
55
50
57
51
49
43
40
57
50
diff
-28
-39
-3
-3
-11
-38
-44
-40
-41
-34
-42
-25
-35
1980
88
103
57
58
64
100
111
104
107
86
92
94
98
1985
81
99
55
55
60
80
93
102
96
95
80
91
81
Females
1990 1995
67
56
71
48
51
47
48
50
56
54
64
54
77
62
84
69
78
61
67
58
59
45
73
57
80
67
2000
53
50
53
55
56
53
59
50
52
44
42
62
49
diff
-34
-53
-4
-3
-9
-47
-52
-54
-55
-42
-49
-32
-49
New Zealand Health Information Service, National Minimum Data Set - Mortality.
New Zealand Health Information Service, National Minimum Data Set - Public Hospital Discharges.
Statistics New Zealand, 1981-2001 Censuses of Population and Dwellings.
The decrease in HUEs roughly followed the pattern of decrease in population-based hospital day rates
except that this was mediated by life-expectancy changes over time. Figure 8.1a presents changes in
standardised bed-day rates and life-expectancy at birth between 1980 and 2000, and Figure 8.1b
shows HUE at birth and at 65 years for the same time period. As life-expectancy increased between
1980 and 2000, bed-days per capita declined. Longer life-expectancy results in a longer period ‘at
risk’ of hospitalisation, so it could be expected that HUEs would increase over this period. However
as is show in Figure 8.1b, increased life-expectancy was more than offset by declines in bed-days per
capita, resulting in a decline in HUE at birth, and at age 65 years over the time period.
81
1.2
79
1.0
77
0.8
75
0.6
73
0.4
71
0.2
69
0.0
1980
1982
1984
1986
1988
1990
Bed-days Males
Life-Expectancy Males
Hospital utilisation expectancy (days) at age x
Figure 8.1b:
Sources:
1992
1994
1996
67
2000
1998
Bed-days Females
Life-Expectancy Females
Hospital Utilisation Expectancy at Birth (Days) and at Age 65 Years,
By Gender, New Zealand
100
Males Age 0
90
Females Age 0
80
Males Age 65
70
Females Age 65
60
50
40
30
20
10
0
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
New Zealand Health Information Service, National Minimum Data Set - Mortality.
New Zealand Health Information Service, National Minimum Data Set - Public Hospital Discharges.
Statistics New Zealand, 1981-2001 Censuses of Population and Dwellings.
During the years 1980 to 1984 there was minimal change in HUE(0), and this period was followed by
another (1985-1992) in which there was a sustained decrease in HUE(0). The 1993-1996 period was
characterised by a one day increase that was driven by a slight increase in e(0)s and by a temporary
plateauing of bed-day rates. This was then followed by a decline in the HUE(0) until 1998 when there
was a reversal.
birth
1.4
Life expectancy (years) at birth
Life-Expectancy at Birth (Years) and Standardised Bed-Days per Capita,
By Gender, New Zealand, 1980-2000
capita
Bed-days per capita
Figure 8.1a:
In 1980, HUE at ages 65 years and over made up approximately two thirds of HUE over the lifetime
(HUE(0)). By 2001, despite the converging of HUE for males and females and the considerable
reduction in HUE at birth and at 65 years (down to about 50 and 40 days respectively), HUE(65)
accounted for an even larger proportion, four fifths of the HUE at birth, indicating a compression of
lifetime hospital use into the 65 and over age group. HUE at birth is thus clearly driven largely by
hospital use at older ages, and much of the analysis in the remaining chapters will focus on what
happens at older ages (see also Section 8.3 below).
Gender Differentials
The lifetime female HUE remained consistently above that for males. This is opposite to the trend
found for the age-standardised hospital bed-days per capita where this measure for males was higher
(see also Chapter 6.4.1). This reflects the effect of the longer life-expectancy of females giving them a
greater period of exposure to the risk of being hospitalised. In 1980, the female HUE(0) was 11
percent higher than that for males but by 2000 the female HUE at birth was only 4 percent higher,
showing that the gender disparity in HUEs had narrowed substantially.
Regional Differentials
Over the 1980-2000 period, in most regions, there were substantial annual decreases in hospital bedday rates and increases in life-expectancy at birth. As has been mentioned, the increase in lifeexpectancy at birth was more than offset by decreases in bed-day rates, resulting in the lifetime
hospital expectancies (HUE(0)) decreasing for all 12 regions, although the extent of the decrease
varied from region to region (see Table 8.1). This widespread decrease was produced by the
substantial decrease in the national HUE(0) for males and females, while regional variation in HUEs
decreased, with the most rapid change occurring between 1985 and 1993 (see detailed data in
Appendix 8.1).
Regional variations from the national HUE(0)s were less for males than females, so the convergence
is more marked in the female figures. While female HUE(0)s were consistently higher than those for
males, the male-female discrepancy declined over the time period in most regions.
In the early 1980s the 12 regions could be roughly divided into three groups according to their
HUE(0) level relative to the New Zealand level:
1. Hawke’s Bay/Tairawhiti, Bay of Plenty/Lakes, Taranaki/Wanganui/Manawatu and
Northland which had HUE(0)s considerably higher than the New Zealand level.
2. Wellington, Waikato, Southern South Island, Nelson/Marlborough and Central South
Island which were at about the New Zealand level.
3. The Waitemata, Auckland Central and South Auckland which had HUE(0)s much lower
than the New Zealand level.
Convergence of the regions in the first group towards the New Zealand level over time was very
marked.



Northland HUE(0) reduced substantially to well below the national level in the early 1990s
but finished just below.
Hawke’s Bay/Tairawhiti maintained the highest HUE(0) level from 1988 to 1997 ending at
about the New Zealand level.
At the end of the review period measures for Taranaki/Wanganui/Manawatu HUE(0)
finished at around the New Zealand level and Bay of Plenty/Lakes just above.
The regions in the second group displayed a variety of patterns.

Nelson/Marlborough started just above the New Zealand level and from 1988 reduced
steeply to the lowest position relative to other regions. By 2000, HUE(0)s were 21 percent
and 20 percent lower than the national levels for males and females respectively.


In the late 1990s the Wellington region HUE(0) dropped relative to the New Zealand level
finishing below with the lowest female HUE(0).
Waikato, Central South Island and Southern South Island started just above New Zealand
finishing with Waikato and Southern South Island around New Zealand level and Central
South Island above New Zealand level.
The third group, comprising the three regions in the Auckland area, is characterised by extremely low
HUE(0) levels relative to the New Zealand level in the early to mid-1980s.



8.3
Unlike the other regions, the absolute levels changed little over the period. South Auckland
HUE(0) converged towards the New Zealand levels in the mid 1990’s, and finished just
above.
From 1993, Auckland Central levels increased in absolute and relative terms to end at a
level above that for New Zealand.
Waitemata remained below the New Zealand level but by a much smaller margin.
CONTRIBUTION OF VARIOUS AGE GROUPS TO LIFETIME
HOSPITALISATION EXPECTANCY
Table 8.2 shows the proportionate contribution of different age groups to the total lifetime HUE. More
than half the total hospital bed-days that a person can expect to spend over a lifetime are likely to
occur after the age of 65 (Appendix Table 8.2 shows detailed age groups). This percentage has
increased over time with the contribution for males going from 48 percent in 1980 to 59 percent in
2000 and that for females 56 percent in 1980 to 64 percent in 2000.1 The proportional contribution to
the total lifetime HUEs by the 75-84 years, 85 years and over have increased significantly, as has that
for the under 1 year age group. Infants (under one year for both genders) and males 85 years and over
were the only categories to show increases in the actual number of bed-days contributed to the total
HUE. The percentage contribution to total HUE(0) for the remaining age groups declined, with ages
15-44 and 45-64 years having the greatest reduction in percent contribution. Because of the
importance of hospitalisation of older people, trends and differentials in the numbers of days expected
to be spent in hospital after age 65 are presented in the next section. In Chapter 9 further
disaggregation by age group is considered.
Table 8.2:
Absolute Contribution (%) 2 of Age Groups to Lifetime Hospital Utilisation
Expectancy, New Zealand, 1980, 1990 and 2000
Age Groups (yrs)
Under 1
1-14
15-44
45-64
65-74
75-84
85+
Total
Sources:
1
1980
2.9
6.7
16.5
25.8
22.7
19.4
6.1
100.1
Males
1990
4.7
5.4
14.0
21.9
22.4
22.6
9.0
100.0
2000
6.9
4.4
11.5
18.6
21.6
24.5
12.6
100.1
1980
2.3
4.4
16.0
21.3
18.8
24.2
13.0
100.0
Females
1990
3.8
3.9
11.9
18.9
19.1
25.7
16.8
100.0
2000
5.6
3.3
10.1
16.9
18.6
26.0
19.4
99.9
New Zealand Health Information Service, National Minimum Data Set - Mortality.
New Zealand Health Information Service, National Minimum Data Set - Public Hospital Discharges.
Statistics New Zealand, 1981-2001 Censuses of Population and Dwellings.
It must be stressed that these data are filtered and exclude maternity cases, so this decline is real and not a function of
decreased confinement rates.
2
The contribution each age group’s hospitalisations had to the overall HUE.
8.4
HOSPITAL UTILISATION EXPECTANCY AT AGE 65 YEARS (HUE (65))
National Trends
Over the period 1980-2000, the number of days, on average, that New Zealanders at age 65 years can
expect to spend in hospital over the rest of their lives decreased by 30 percent (from 52 days to 36
days) for males, and by 35 percent (from 59 to 38 days) for females (see Table 8.3 and Appendix
Table 8.2). The percentage decrease in the expected number of days to be spent in hospital at age 65
(HUE(65)) was slightly lower than the number expected at birth (HUE(0)) showing that greater
decreases occurred among younger people.
The early 1980s were characterised by a small increase in HUEs at age 65 years. This was due to
relatively stable hospital day rates at older ages but in conjunction with an increase in lifeexpectancies. The net result was that the period of exposure to the risk of hospitalisation has
increased, while the discharge rates remained the same. From 1985, the HUE (65) decreased more or
less continuously until 1998, except for a flattening of the curve between 1992 and 1994, but there
was a slight increase from 1998 to 2000. The 5-year period from 1987 to 1992 was a period of
substantial decrease, accounting for two thirds of the total decrease in HUEs over the entire 20-year
period. As already noted, HUEs at the age of 65 years accounted for over half of the HUE at birth, for
both females and males.
Table 8.3:
Hospital Utilisation Expectancies (Days) at Age 65 Years, By Gender and
Region, Selected Years, 1980-2000
Region
New Zealand
Northland
Waitemata
Auckland Central
South Auckland
Waikato
BoP/Lakes
H. Bay/Tairawhiti
Taran./Wang./Man.
Wellington
Nelson-Marlb.
Central S. Island
Southern S. Island
Sources:
1980
52
54
35
30
38
63
62
58
62
56
51
59
56
1985
50
60
33
32
37
52
54
54
56
62
44
59
50
Males
1990 1995
44
37
43
28
34
32
31
34
35
35
41
35
51
40
51
43
47
41
44
38
35
31
51
38
51
44
2000
36
31
37
38
38
34
39
37
34
31
27
43
36
diff
-16
-23
2
8
-1
-28
-23
-21
-28
-25
-24
-16
-20
1980
59
67
37
30
38
67
73
68
76
63
61
70
65
1985
59
68
40
34
41
57
62
75
69
75
56
72
55
Females
1990 1995
48
40
51
31
36
33
32
36
38
37
45
38
50
43
61
50
55
44
52
42
42
32
56
41
58
47
2000
38
33
41
41
39
36
42
35
37
32
31
47
35
diff
-21
-35
3
11
1
-31
-30
-32
-40
-31
-31
-24
-29
New Zealand Health Information Service, National Minimum Data Set - Mortality.
New Zealand Health Information Service, National Minimum Data Set - Public Hospital Discharges.
Statistics New Zealand, 1981-2001 Censuses of Population and Dwellings.
Gender Differentials
The female HUE at age 65 years was consistently above that for males. In 1980 female HUEs were 13
percent higher than those for males. By 2000, the female HUE at age 65 years (37 days) was only 6
percent higher than that of the male HUE (35 days) showing that, as with HUE(0), the gender
disparity in HUE had narrowed substantially.
Regional Differentials
The Hospital Utilisation Expectancy at age 65 years decreased over time for 9 out of 12 regions with
the three Auckland regions being the exception. The relative rankings of the regional HUE(65) are
similar to those for HUE(0) with the following exceptions (see Table 8.3 and Appendix Table 8.3):

Females in Central South Island had mid-level HUE(0) rankings across the entire period,
whereas HUE(65) rankings were very high throughout.

Northland’s HUE(65) was closer to the New Zealand average than HUE(0) early in the
period, and (as with HUE(0)) saw a decline over the time period, dropping to below the New
Zealand average by the 1990s. This decline in HUE(65) was probably a function of inmigration of well-off retired persons (Lepina and Pool 2000).
8.5
HOSPITAL UTILISATION EXPECTANCIES BY ETHNICITY
8.5.1
Lifetime Hospital Utilisation Expectancies at Birth (HUE (0))
Of the various health indices presented in this report HUEs will be most affected by the issues
surrounding Māori data noted in Chapters 3 and 4. This is because the HUE is reliant on three
separate sources of data whereas mortality measures such as life-expectancy rely on only two sources.
Due to this, the results presented here should be viewed as indicative rather than definitive. Because
numbers are small variance could also be a function of random statistical effects rather than real
differentials. To limit this effect, larger regional groupings were used in order to dampen random
statistical variations. However, as presented in the last section and previous chapters, there is
substantial regional variation in health measures, and an uneven distribution of Māori population
between regions. Thus differences between Māori and total population HUEs could be partly an
artefact of region of residence and must therefore be interpreted carefully. Because of smaller
numbers and similar data issues, Pasifika and Asian HUEs are fraught with far greater problems than
for Māori, and thus no regional analysis is undertaken here. As with the other indicators analysed
earlier in this report the South Island has been excluded from the analysis because of small Māori
numbers.
The results relate to the socio-cultural Māori population (except for 1981) as explained in Chapters 3
and 4 (the alternative sole Māori population denominator for 1990-94 shown in Appendix Table 8.4).
Figure 8.3 and Appendix Table 8.4 show national and regional Māori HUEs at birth for the 1980-84,
1990-94 and 1996-2000 periods.
There is considerable variation in Māori HUEs between regions, some of which could be an artefact
of different practices in the coding of ethnicity, for mortality data as well as hospital discharge data.
Caveats about variable data quality aside, however, there is a clear indication that Māori HUEs at
birth are initially substantially higher than HUEs for the total population of New Zealand (see Table
8.3). In this regard, this involves higher bed-day rates in the context of lower survivorship, although
by 1996-2000 the Māori HUE is lower than that for the total population. This is discussed in further
detail later on.
Regionally, in 1980-84 and 1990-1994 Māori HUEs were higher than the total HUEs for all regions.
In 1996-2000 the opposite occurred with most regions having a higher total than Māori HUE, the
exceptions being Northland, both genders, and Hawke’s Bay/Tairawhiti (females only). 3
3
Data problems may account in part for the extremely high HUEs seen for the Hawke’s Bay/Tairawhiti region. The malefemale HUE discrepancy for this region is also very wide for 1980-1984. This gap was not apparent in1996-2000. All this
indicates that data quality and quantity has a greater effect on Māori HUEs than on those for the total population making
direct comparisons more difficult.
Hospital Utilisation Expectancy at birth (days)
200
200
Sources:
8.5.2
National and Regional Māori Hospital Utilisation Expectancies at Birth (Days),
By Gender and Larger Health Regions, Selected 5-Year Averages, 1980-2000
Hospital Utilisation Expectancy at birth (days)
Figure 8.3:
1980-84
Males
180
1990-94
160
1996-00
140
120
100
80
60
40
Taranaki/Wanganui/
Manawatu/Wellington
Hawkes
Bay/Tairawhiti
Bay of Plenty/Lakes
Waikato
Auckland
Northland
0
NEW ZEALAND
20
1980-84
Females
180
1990-94
160
1996-00
140
120
100
80
60
40
Taranaki/Wanganui/
Manawatu/Wellington
Hawkes
Bay/Tairawhiti
Bay of Plenty/Lakes
Waikato
Auckland
Northland
0
NEW ZEALAND
20
New Zealand Health Information Service, National Minimum Data Set - Mortality.
New Zealand Health Information Service, National Minimum Data Set - Public Hospital Discharges.
Statistics New Zealand, 1981-2001 Censuses of Population and Dwellings.
Hospital Utilisation Expectancy at Age 65 Years (HUE(65))
Elderly Māori, (both genders and all regions) at the beginning of the period could expect to spend
longer in hospital than the Total elderly population (see Table 8.4). However, as with HUE(0),
HUE(65) for Māori decreased so markedly that by the end of the 1990s they were lower than those for
the total population, both nationally and regionally. In general, both Māori and Total population in the
Auckland and Waikato had the most favourable HUE(65)s, and those in Hawke’s Bay/Tairawhiti
and Bay of Plenty/Lakes the least favourable. Both groups of elderly in Manawatu/Wellington
showed dramatic improvements in this measure, being above the national levels at the start of the
review period but below this benchmark at the end. This synchronicity between Māori and total
population in regional trends may in part be explained by variations in provision of services for the
elderly.
Table 8.4:
Māori and Total Population Hospital Utilisation Expectancy (Days) at Age 65
Years (Hue (65)), By Gender and Larger Health Regions, Selected 5-Year
Averages, 1980-2000
Region
NEW ZEALAND
Northland
Auckland Metro
Waikato
The Bay of Plenty/Lakes
Hawke’s Bay/Tairawhiti
Taranaki/Wanganui/
Manawatu/Wellington
Region
NEW ZEALAND
Northland
Auckland Metro
Waikato
The Bay of Plenty/Lakes
Hawke’s Bay/Tairawhiti
Taranaki/Wanganui/
Manawatu/Wellington
Sources:
Māori Population
1980-844
1990-945
Males Females Males Females
111
115
77
86
112
115
69
81
87
83
63
65
94
101
68
70
108
102
74
80
163
183
129
139
127
137
90
107
1996-20006
Males Females
46
49
49
51
47
46
44
48
52
59
52
56
43
47
Total Population
1980-84
1990-94
Males Females Males Females
79
89
58
62
91
109
57
63
57
60
48
50
85
97
57
61
97
112
67
72
97
108
71
76
84
100
61
65
1996-2000
Males Females
50
53
47
48
50
52
48
53
55
58
54
56
48
51
New Zealand Health Information Service, National Minimum Data Set - Mortality.
New Zealand Health Information Service, National Minimum Data Set - Public Hospital Discharges.
Statistics New Zealand, 1981-2001 Censuses of Population and Dwellings.
8.6 CONCLUSION
One of the key features of how HUEs behave with respect to their underlying components is
illustrated by the findings for males and females. Despite males having characteristically lower LE
(due to higher male mortality) and higher hospital bed-day rates, male HUEs are consistently lower
than those of females. This highlights the fact that, on a population base, males can expect to spend
fewer days in hospital because they have less opportunity to be hospitalised than females, a function
of their shorter life-expectancy. The narrowing of differences in both male and female mortality and
hospitalisation accounts for the narrowing of gender-specific HUEs.
The unexpectedly low Māori HUE seen in 1996-2000 could be interpreted in many ways. It could be
related to Māori having lower life-expectancy even though the bed-day rate is higher, 7 however
evidence in Chapter 6 found that age-standardised bed-day rates per capita for Māori , while above
those seen for the total population, were declining over this period (see Table 6.5). Alternatively it
may be a factor of declining Māori bed-day rates per capita regardless of life-expectancy, a ‘real’
improvement in health. However supply and demand factors must be considered when interpreting
HUEs in relation to health outcomes. The low Māori HUEs may be an artefact of the ethnicity coding,
or a further possibility is that they are a result of the spatial distribution of Māori in New Zealand. It
could be that Māori disproportionately live in areas with either low demand for, or poor supply of
hospital services.
4
1981 59% or more Māori population is used as denominator
1991 socio-cultural Māori population is used as denominator
6
1999 estimated by linear interpolation using the socio-cultural Māori population at the 1996 and 2001 censuses
7
Research in progress by Ian Pool on the relationship between HEs and cohort survivorship is relevant here. Māori and nonMāori HEs at older ages vary little, but Māori survivorship to these older ages is much lower (Pool 2009).
5
This example illustrates an important point. HUEs can be low as a result of both high levels of
mortality and low levels of hospitalisation and therefore reflect both. Thus, such HUEs are a measure
that truly combines health status and hospital utilisation, and as such need to be interpreted with
reference to health status and utilisation. They do not summarise either component on their own.
Interpretation of HUEs and disaggregation of the supply and demand factors that influence them are
discussed further in Chapter 10.
The relatively stable HUE(0) in the early 1980s is a function of decreasing mortality (as measured by
age-standardised rates) in conjunction with the slight drop in bed rates occurring at the time. The
corresponding HUE(65) which increased slightly from 1982 to 1983 is due to the slight increase in
bed-day rates for people 75 years and over, in conjunction with constant LE(65).
The results presented support the Fries hypothesis of increasing longevity accompanied by decreasing
morbidity. A combination of rapid decreases in the hospital bed-day rates (age-standardised) and
constant decreases in mortality (corresponding to a substantial increase in life-expectancy at birth
especially from 1986 to 1991) accounts for the significant drop in HUE(0) in the 1984-1992 period.
This indicates that despite the increased period at risk of being hospitalised, the age-specific decrease
in hospital bed-day rates more than offset this, leading to an overall decline in lifetime HUE. The
slightly less dramatic decrease in HUE(65) during this period is due to the larger survivorship gains
made in the age groups under 65 years. The gradual but constant further decrease in HUE(0) and
HUE(65) from 1992 to 1998 reflects the continuing declines in both mortality and bed-day rates
during that time. The slight increase in HUE(0) and HUE(65) between 1998 and 2000 is a function of
the still increasing life-expectation yet stabilisation of bed-day rates.
Thus the substantial reductions in HUEs over the 21 years can be explained by changes in health
status as reflected in mortality patterns (and thus LEs) and hospital utilisation. The latter, in turn, was
also influenced by significant changes in clinical and hospital management practices driven by
political, economic and technological transformations. In general, as will be shown in the next
chapter, the percentage reduction in HUE was greater for younger than older people. This was
because improved life-expectancy for older people meant that this, paradoxically, extended the length
of time they were at risk of hospitalisation. In contrast, for younger people most longer-term
improvements in survivorship had been achieved by the 1980s, and thus their HUEs were most
affected by hospitalisation.
This chapter has highlighted the importance of looking at HUEs at different ages, and the large
contribution of hospitalisation at older ages to lifetime HUEs. The next chapter looks at this in more
detail, investigating trends in HUEs for different stages of the life-cycle. Chapter 10 and those
following then attempt to tease out the contributing influences of supply and demand on HUE levels
and discusses interpretation in greater depth.