1 analysing long-term trends in sickness and health: further evidence from the hampshire friendly...
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Analysing long-term trends in sickness and health: further evidence from the Hampshire Friendly Society
Bernard Harris, Martin Gorsky , Aravinda Guntupalli and Andrew HindeLongitudinal data from historical sourcesUniversity of Guelph, 24/5/10
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1. Introduction
• Hampshire (and General) Friendly Society
• History of morbidity
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2. The Hampshire Friendly Society and its members
• ‘County’ or patronised society
• Founded in Winchester in 1824
• Based in Hampshire in southern England
• Majority of members were rural working-class males (no women admitted to the Assurance Section after 1877)
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3. Research aims
• Identify members on joining• Use sickness benefits to identify sickness
episodes• Trace these from joining to departure/death• 10% sample of all members joining the
assurance section (but note that not all the members who joined the assurance section were men who were eligible for sickness benefit)
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4. Sources
Assurance ledgers Period covered Sickness episodes Cause of sickness
Series 1 1825- 1867 Total payments (43 years)
X
Series 1 1868- 1894 Annual payments X
Series 2 1895- 1931 Sick days per quarter
Series 3 1895- 1931 Sick- days per quarter
Record cards Period covered Sickness episodes Cause of sickness
Series 1 1931- 1981 Sick- days per quarter
Series 2 (incomplete) 1931- 1981 Sick- days per quarter
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5. Research questions
• Seasonality of sickness claims
• Age-of-onset of ‘chronic’ morbidity
• Changes in age-specific morbidity over time
• Causes of sickness claims
• Changing pattern of morbidity
• Cause-specific morbidity and age-specific morbidity
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6. Seasonal patterns
Figure 1. HFS: Sickness episodes per quarter
70
80
90
100
110
120
130
140
150
Jan- Mar Apr- Jun Jul- Sep Oct- Dec
Quarter
Index
(aver
age=
100)
1825- 1879 1880- 1914 1915- 1939
Figure 2. HFS: Sickness days per quarter
70
80
90
100
110
120
130
Jan- Mar Apr- Jun Jul- Sep Oct- Dec
Quarter
Index
(aver
age=
100)
1825- 1879 1880- 1914 1915- 1939
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7. Morbidity and age
Figure 3. Sickness prevalence by age, 1870- 1949
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
65- 7060- 6555- 6050- 5545- 5040- 4535- 4030- 3525- 3020- 25
age group (years)
sick
-yea
rs p
er m
an-y
ear
1870- 89 1890- 1909 1910- 29 1930- 49
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9. Three gauges of morbidity
• Incidence = no. of sickness episodes
• Duration = length of episodes
• Prevalence = no. of ‘sick-years’ per head of population exposed to risk
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9. Three gauges of morbidity, cont.
• Problems in measuring the incidence of sickness episodes– Cannot identify separate episodes within the same
quarter– Cannot definitely identify episodes which extend
across quarters– Assume that all the sick-days within a given quarter
formed part of a single episode within that quarter– Assume that sickness-periods in consecutive quarters
formed part of a single episode unless there is clear evidence to the contrary
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9. Three gauges of morbidity, cont.
• If we can estimate incidence, we can calculate duration:
Incidence
evalenceDuration
Pr
•So our method of estimating incidence yields a lower estimate of the total number of episodes (incidence) and a higher estimate of sickness duration•But this is only a problem if we think that the extent to which we may have underestimated the incidence of sickness episodes changed over time
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10. Age-specific sickness rates
Figure 6. Incidence of sickness episodes by age- group over time
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
1870- 74 1880- 84 1890- 94 1900- 04 1910- 14 1920- 24 1930- 34 1940- 44
Period
Epis
odes
per
man
-ye
ar
20- 35 35- 50 50- 65 65- 70
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10. Age-specific sickness rates, cont.
Figure 7. Trend in average duration of recorded sickness (minimum
incidence)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
1870- 74 1880- 84 1890- 94 1900- 04 1910- 14 1920- 24 1930- 34 1940- 44
Period
Years
per
epsi
ode
20- 35 35- 50 50- 65 65- 70
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10. Age-specific sickness rates, cont.
Figure 8. Trends in recorded sickness prevalence by age
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
1870- 74 1880- 84 1890- 94 1900- 04 1910- 14 1920- 24 1930- 34 1940- 44
Period
Sic
k-years
per
man-year
20- 35 35- 50 50- 65 65- 70
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11. The proximate causes of sickness claims
• Problems associated with the use of epidemiological descriptions and categories– Interpretation of handwriting– Diagnostic changes– Numbers of categories– Use of ICD chapters
• Age problems– Focus on 40-64 year olds
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11. The proximate causes of sickness claims, cont.
Quarterly episodes Quarterly episodes (% of total)
ICD chapter coding Aged 40- 64 at time of sickness
1871-90
Joiners
1891-1914
Joiners
1915-39
Joiners Total 1871- 90 Joiners
1891-1914
Joiners 1915- 39 Joiners Total
I (phthisis, etc.) Phthisis, etc. 98 164 27 289 3.21 4.52 0.56 2.52
I (other) Other infectious & parasitic diseases 46 58 69 173 1.51 1.60 1.44 1.51
II Neoplasms 51 31 27 109 1.67 0.85 0.56 0.95
III Diseases of the blood, etc. 9 13 13 35 0.30 0.36 0.27 0.31
IV Endocrine, nutritional and metabolic diseases 19 4 54 77 0.62 0.11 1.13 0.67
V Mental and behavioural disorders 77 93 166 336 2.52 2.56 3.47 2.93
VI Diseases of the nervous system 211 129 115 455 6.92 3.55 2.40 3.97
VII- VIII Diseases of the eyes and ears 54 149 56 259 1.77 4.10 1.17 2.26
IX Diseases of the circulatory system 234 392 563 1,189 7.67 10.79 11.77 10.37
X (asthma) Asthma 83 36 63 182 2.72 0.99 1.32 1.59
X (bronchitis, etc.) Bronchitis, etc. 176 241 410 827 5.77 6.64 8.57 7.21
X (colds, etc.) Colds, etc. 417 523 540 1,480 13.67 14.40 11.29 12.91
X (other) Other diseases of the respiratory system 49 116 183 348 1.61 3.19 3.83 3.04
XI Diseases of the digestive system 145 289 380 814 4.75 7.96 7.94 7.10
XII Diseases of the skin, etc. 96 107 128 331 3.15 2.95 2.68 2.89
XIII Diseases of the musculoskeletal system 612 466 864 1,942 20.07 12.83 18.06 16.94
XIV Diseases of the genitourinary system 45 62 130 237 1.48 1.71 2.72 2.07
XVIII Symptoms, signs etc. 216 194 322 732 7.08 5.34 6.73 6.38
XIX Injuries etc. 291 498 535 1,324 9.54 13.71 11.18 11.55
No information Unclassified 5 3 0 8 0.16 0.08 0.00 0.07
Unclassified No information 116 64 139 319 3.80 1.76 2.91 2.78
Total 3,050 3,632 4,784 11,466 100.00 100.00 100.00 100.00
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11. The proximate causes of sickness claims, cont.
Age 40- 64 Joiners 1871- 1890 Joiners 1891- 1914 Joiners 1915- 39 All Joiners
ICD chapter coding Days Days Days Days
Phthisis, etc. I (phthisis, etc.) 68.08 71.29 58.05 69.10
Other infectious & parasitic diseases I (other) 18.80 21.67 18.28 19.54
Neoplasms II 47.94 46.65 43.64 46.50
Diseases of the blood, etc. III 42.33 39.40 40.25 40.58
Endocrine, nutritional and metabolic diseases IV 38.94 58.25 47.22 45.68
Mental and behavioural disorders V 66.60 57.91 50.04 55.95
Diseases of the nervous system VI 74.24 72.09 61.66 70.59
Diseases of the eyes and ears VII- VIII 45.17 57.36 32.92 49.47
Diseases of the circulatory system IX 61.34 54.59 54.66 55.97
Asthma X (asthma) 51.05 27.31 29.37 38.87
Bronchitis, etc. X (bronchitis, etc.) 30.66 31.25 31.27 31.14
Colds, etc. X (colds, etc.) 17.35 17.35 16.57 17.07
Other diseases of the respiratory system X (other) 21.23 29.16 23.77 25.21
Diseases of the digestive system XI 29.22 37.31 28.91 31.92
Diseases of the skin, etc. XII 24.90 22.50 20.99 22.62
Diseases of the musculoskeletal system XIII 32.81 27.04 40.48 34.70
Diseases of the genitourinary system XIV 35.52 37.84 49.72 43.93
Symptoms, signs etc. XVIII 25.74 28.79 29.30 28.11
Injuries etc. XIX 23.72 32.22 26.45 28.01
Unclassified Unclassified 43.96 32.60 40.02 39.95
No information No information 10.00 22.67 0.00 16.33
Total 36.60 36.12 34.59 35.62
Average age of members experiencing sickness 53.54 53.10 52.26 52.87
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11. The proximate causes of sickness claims, cont.
Age 40- 64 Joiners 1871- 1890 Joiners 1891- 1914 Joiners 1915- 39 All Joiners
ICD chapter coding Total days Total days Total days Total days
Phthisis, etc. I (phthisis, etc.) 5.98 8.91 0.95 4.89
Other infectious & parasitic diseases I (other) 0.77 0.96 0.76 0.83
Neoplasms II 2.19 1.10 0.71 1.24
Diseases of the blood, etc. III 0.34 0.39 0.32 0.35
Endocrine, nutritional and metabolic diseases IV 0.66 0.18 1.54 0.86
Mental and behavioural disorders V 4.59 4.11 5.02 4.60
Diseases of the nervous system VI 14.03 7.09 4.28 7.87
Diseases of the eyes and ears VII- VIII 2.18 6.52 1.11 3.14
Diseases of the circulatory system IX 12.86 16.31 18.60 16.30
Asthma X (asthma) 3.80 0.75 1.12 1.73
Bronchitis, etc. X (bronchitis, etc.) 4.83 5.74 7.75 6.31
Colds, etc. X (colds, etc.) 6.48 6.92 5.41 6.19
Other diseases of the respiratory system X (other) 0.93 2.58 2.63 2.15
Diseases of the digestive system XI 3.79 8.22 6.64 6.36
Diseases of the skin, etc. XII 2.14 1.84 1.62 1.83
Diseases of the musculoskeletal system XIII 17.98 9.60 21.13 16.50
Diseases of the genitourinary system XIV 1.43 1.79 3.91 2.55
Symptoms, signs etc. XVIII 4.98 4.26 5.70 5.04
Injuries etc. XIX 6.18 12.23 8.55 9.08
Unclassified Unclassified 0.20 0.07 0.00 0.08
No information No information 1.04 1.11 0.00 1.28
Total 100.00 100.00 100.00 100.00
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12. Sickness-cause and sickness-age
% of all episodes in each group Age at time of
sickness episode Percentage of sickness episodes in each age group in each quarter
<20 20- 29 30- 39 40- 49 50- 59 60- 69 70- 79 >79 All ages
Phthisis, etc. I (phthisis, etc.) 0.66 3.16 3.72 3.60 1.90 0.88 0.28 0.00 2.04
Other infectious & parasitic diseases I (other) 8.18 5.49 3.45 1.69 1.61 1.11 0.99 0.11 2.60
Neoplasms II 0.17 0.05 0.41 0.38 1.22 1.08 1.79 1.31 0.80
Diseases of the blood, etc. III 0.28 0.05 0.34 0.14 0.45 0.23 0.09 0.00 0.22
Endocrine, nutritional and metabolic diseases IV 0.00 0.00 0.02 0.36 0.76 1.29 1.27 0.00 0.59
Mental and behavioural disorders V 0.66 1.39 3.21 2.86 2.80 2.01 1.24 1.75 2.17
Diseases of the nervous system VI 0.50 0.25 2.52 3.89 3.79 5.07 6.74 8.21 3.67
Diseases of the eyes and ears VII- VIII 0.88 1.47 1.03 2.15 1.92 3.47 5.85 6.13 2.59
Diseases of the circulatory system IX 1.49 1.62 3.14 3.63 9.15 21.81 23.60 15.55 10.48
Asthma X (asthma) 0.11 0.75 1.30 1.34 1.44 1.53 1.55 0.22 1.22
Bronchitis, etc. X (bronchitis, etc.) 2.49 2.98 3.07 5.18 8.02 8.62 12.12 15.01 6.68
Colds, etc. X (colds, etc.) 23.16 20.71 19.22 17.02 12.12 6.24 2.51 1.10 13.04
Other diseases of the respiratory system X (other) 7.74 7.04 5.45 3.41 2.91 1.54 0.87 0.00 3.60
Diseases of the digestive system XI 5.75 7.09 7.65 6.61 7.65 6.71 7.15 7.78 7.06
Diseases of the skin, etc. XII 7.52 6.22 5.45 4.34 2.37 1.98 2.10 0.66 3.77
Diseases of the musculoskeletal system XIII 4.59 8.18 11.37 17.52 18.33 17.75 20.72 30.56 15.52
Diseases of the genitourinary system XIV 1.05 1.07 1.42 1.46 2.45 2.40 1.24 2.85 1.75
Symptoms, signs etc. XVIII 7.52 8.65 7.53 6.90 6.93 5.34 3.53 3.72 6.47
Injuries etc. XIX 24.49 21.38 16.58 14.30 11.36 7.77 4.48 5.04 12.99
Unclassified Unclassified 2.54 2.36 3.02 3.06 2.78 3.09 1.89 0.00 2.66
No information No information 0.22 0.10 0.10 0.14 0.02 0.10 0.00 0.00 0.09
Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00
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12. Sickness-cause and sickness-age, cont.
Age at time of
sickness episode Average number of sick days per sickness episode in each quarter
ICD chapter coding <20 20- 29 30- 39 40- 49 50- 59 60- 69 70- 79 >79 All ages
Phthisis, etc. I (phthisis, etc.) 36.09 53.57 56.98 67.96 70.48 69.51 56.33 - 61.68
Other infectious & parasitic diseases I (other) 16.82 20.58 16.74 16.24 21.22 27.79 47.37 30.00 20.37
Neoplasms II 19.67 22.00 32.76 37.81 48.78 49.00 62.08 52.64 49.41
Diseases of the blood, etc. III 48.00 23.00 39.54 40.60 46.67 26.75 20.33 - 38.77
Endocrine, nutritional and metabolic diseases IV - - 8.00 40.79 42.17 65.28 63.67 - 56.82
Mental and behavioural disorders V 33.55 36.50 56.34 58.65 55.73 56.50 72.72 65.87 55.45
Diseases of the nervous system VI 48.38 47.80 71.33 70.73 71.02 69.56 71.75 74.23 70.53
Diseases of the eyes and ears VII- VIII 23.50 22.50 21.43 37.92 48.69 64.95 70.79 73.14 54.51
Diseases of the circulatory system IX 18.22 30.42 38.52 41.07 52.71 62.88 66.13 61.06 58.71
Asthma X (asthma) 22.00 24.50 32.20 28.39 35.00 55.47 69.61 78.00 42.66
Bronchitis, etc. X (bronchitis, etc.) 16.16 20.36 21.90 24.74 29.55 42.04 53.43 62.93 37.75
Colds, etc. X (colds, etc.) 12.23 12.99 13.00 15.29 17.86 20.31 29.05 33.00 15.20
Other diseases of the respiratory system X (other) 14.39 14.81 17.13 20.20 25.14 32.86 39.77 - 19.57
Diseases of the digestive system XI 22.24 22.22 28.27 27.23 30.84 46.21 63.96 67.60 36.03
Diseases of the skin, etc. XII 13.07 15.06 17.56 19.71 26.52 36.79 56.00 35.20 22.11
Diseases of the musculoskeletal system XIII 17.99 23.75 25.01 30.76 34.22 48.59 63.90 69.65 41.38
Diseases of the genitourinary system XIV 26.63 31.62 26.51 27.78 49.85 49.59 57.58 58.00 42.79
Symptoms, signs etc. XVIII 13.05 17.96 16.10 22.21 29.67 39.36 45.16 67.35 26.09
Injuries etc. XIX 16.27 20.32 21.16 22.85 29.21 41.34 61.70 74.34 26.37
Unclassified Unclassified 17.89 27.47 32.21 42.73 38.63 49.44 51.82 - 39.25
No information No information 12.50 12.25 25.00 18.00 8.00 - - - 16.50
Average (all causes) 15.86 20.10 24.34 29.09 35.27 49.47 61.51 66.53 35.98
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13. What else can we do with these data?• The determinants of sickness episodes
– Factors associated with the initiation of sickness episodes
– Factors associated with the duration of sickness episodes
• Links with other HFS data– Date and place of birth– Occupation on joining– Benefit entitlements– HFS administrative data– HFS financial data
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13. What else can we do these data, cont.• Links with other data sources
– Wage rates– Meteorological data– Unemployment data– Local mortality data– Individual death certificates– Medical registers
• Other research questions– Migration– Welfare provision