Medication, Co-morbidity and Injury in Older Farmers

Don VoaklanderSchool of Public Health

University of Alberta

2

Today’s Talk• Introduction

• Co-morbidity

• Medication Use

• Alberta Study

• Recommendations

3

• Agriculture is one of the most dangerous occupations in Canada

• Within the farm population, the older farmer has been identified to be at greater risk– Unlike other occupations, farmers continue to

contribute to farm operations well beyond the “normative” retirement age

Introduction

4

Rates of Work-Related Fatalities by Age (per 100,000 farm population)

Rates of Work-Related Fatalities by Age (per 100,000 farm population)

7.512.0 10.9 10.8

15.2

48.7

8.6

24.1

93.8

35.7

12.2 13.7

0

10

20

30

40

50

60

70

80

90

100

Rate

/ 1

00,0

00 p

er y

ear

5

Work Related Injury Rates by Age (per 100,000)

Work Related Injury Rates by Age (per 100,000)

89.3

175.3 174.3160.8

180.8

328.5

82.8

248.1

402.1

280.8

162.0 158.4

0

50

100

150

200

250

300

350

400

450

500

Rate

/ 1

00,0

00 p

er y

ear

6

• Intervention points with older farmers are difficult– Work is self paced– Work is part of the farmer’s identity– Work styles and habits may be very hard to change or

influence

• Medication monitoring and management may be a plausible intervention point

• Care of significant co-morbidity may help prevent injury

Why Medication Use and/or Co-morbidity Management

7

Setting the Stage

• There are limited analytic studies examining health risk factors for injury in the farming community– From Canadian data on farmers aged 60 and older

• Fatalities related to operation of tractors and other machinery

• Most common hospitalized injury due to falls– Non machinery and machinery related

• Therefore health risk factor information from numerous fall and motor vehicle collision studies will also be presented

8

• Falls– Issues related to a persons ability to balance during

walking, climbing and interaction with the environment

• Driving– Like machinery operation, driving is a complex task that

requires:• Accurate sensory input

• Rapid information processing

• Reliable judgment

• Fast motor responses

Setting the Stage

9

Disease Factors Related Farm Injury

• Hearing deficit and tinnitus – Can prevent awareness of hazardous situations

• Machinery – extraneous maintenance or blockage problems

• Avoidance of hazards– Sensory awareness of environment

– Communication of hazards between workers and bystanders

10

Disease Factors Related Farm Injury

• Muscular-skeletal problems, back pain, arthritis, previous injury– Inability to react to a dynamic environment– Guarding pain –

• Decreased mobility• Balance issues

– Gait problems• Foot drop or insufficient lift

– Insufficient strength– Insufficient rehabilitation and conditioning

• Premature return to work

11

Disease Factors Related Farm Injury

• Other Factors– Depression

• No hypothesized reason– Lack of self-care?

– Asthma• Hypersensitivity and other allergic reactions may lead

to altered reaction to mechanical stressors

• Also related to depression/injury in other labour sectors

– Sleep quantity/disturbance

12

Disease Factors Related to Falls

• Often an array of conditions is involved– Generally balance related

• Walking, climbing

• Rapid movements

• Reaction/Reflex

– Combined with age related declines• Sensory awareness, slower reaction time and reflexes,

poor vision, muscle strength

13

Disease Factors Related to Falls

• Vision– Vision is declines over time

• cataracts

– Poorer at night

• Incontinence– Distraction and/or haste

• Hypotension– Orthostatic– Post-prandial

• Cardiac arrythmias• Transient ischemic attacks

14

Disease Factors Related to Falls• Peripheral neuropathy

– Diabetes, alcoholism, malnutrition

• Arthritis• Dementia

– Avoidance of hazards

• Gait disorders– Parkinsonism

• Past stroke• Chronic inactivity

– Lost of muscle strength/endurance/coordination

• Sleep disturbance

15

Disease Factors Related to Motor Vehicle Related Injury

• Vision• Hypotension• Dementia• Muscle strength• Joint flexibility• Neurological disorders• Hearing impairment• Hypoglycemia (Diabetes)

16

Medication Use and Older Persons• Medication reaction with older persons is

poorly understood– Pharmacokinetics

• Process of what the body does to the drug

– Pharmacodynamics• Process of what the drug does in the body

– Polypharmacy• Multiple medication use

– Prescription and over-the-counter

17

Pharmacokinetics• Four Components

– Absorption• Virtually the same for young and old

– Distribution• Changes in body composition in older persons alter

drug distribution

– Metabolism• Slower in older persons

– Excretion• Decreased renal blood flow leads to delayed elimination

18

Pharmacodynamics

• Little research has been done in this area– Few drug trials are conducted with older persons– However, there is some evidence that older

persons are more sensitive to medications of the same dose when compared to younger persons

• May be related to altered pharmacokinetics– Distribution, metabolism, excretion

19

Polypharmacy• New or improved drug treatments are regularly added to a

physicians available treatments• Multiple diseases in older individuals predispose them to

multiple treatments– Can be as high as 12-15 prescription and OTC medications at once

• On there own, drug side-effects are often predictable but in combination can cause unexpected:– Disorientation– Confusion– Altered balance abilities– Hypotension– Sedation

20

Medication and Injury in Farmers• Use of any prescription medication

• Stomach medication– Farm stress

• Heart Medication– Altered blood flow/hypotension

• Anti-depressants

21

Medication Use and Falls/MVCs• Benzodiazepines (falls and MVCs)

– Commonly used to treat sleep disturbances in older persons• Depression/anxiety

• Restless leg syndrome

• Dementia

• Blood pressure drugs (falls)• Beta blockers (falls)

– Altered heart rate

• Laxatives (falls)• Anti-depressants (falls and MVCs)

Don Voaklander1, Karen Kelly1, Brian Rowe1, Niko Yiannakoulias1, Larry Svenson2, Don

Schopflocher2, Will Pickett3

1University of Alberta2Alberta Health and Wellness3Queen’s University

23

Acknowledgement

• This research was funded by the Canadian Institutes of Health Research

24

• Methods– Data sources

• Data were gathered from 5 provincial registries: • Alberta Ministry of Health and Wellness databases• Maintains computerized records of all hospital, emergency department,

and medical services – Data include demographic information, admission and discharge dates, and

multiple ICD-9-CM diagnostic and procedure codes– All physician claims include up to 3 diagnosis codes (ICD-9-CM for each

patent encounter)

• Alberta Blue Cross Drug Plan– Collects information on all reimbursed medications used by Albertans aged 65

and older

• Alberta Agriculture Farm Fuel Tax Subsidy List– List of farmers who received a fuel tax rebate for the use of fuel in farm

machinery

25

• Methods (cont.)– Inclusion criteria

• Any farm related injury treated in an Alberta ED or admitted to hospital between the April 1, 1997 and March 31, 2000 that was suffered by a farmer identified by linkage between health data and the Alberta Agriculture Farm Fuel Tax Subsidy List.

– Case definition

• Hospital/ED visits related to injury from agricultural machinery were identified by the presence in the electronic hospital separation abstract of the ICD9-CM E-code E919.0. Other machinery and non-machinery injuries were identified by the presence of the ICD9-CM E-code for location of injury E849.1 that indicates the injury took place on a farm as well as a concurrent E-code specifying an injury from another machinery type (eg. powered hand tools – E920.1, metal working machines E919.3, etc. or a non-machinery injury (eg. fall from or out of a building E882, butted or gored by animal E906.8).

• If a person had more than one hospital/ED visit for an agricultural injury during the study period, the case was restricted to the first one.

26

• Methods (cont.)– Co-morbidity Classifications

• disorders of the eye (ICD9-CM codes 360-379) • incontinence or urinary tract problems (ICD9-CM code 788)• nutritional deficiencies (ICD9-CM codes 260-269)• Parkinson’s disease (ICD9-CM code 332)• osteoarthritis (ICD9-CM codes 715-716)• dementia/cognitive impairment (ICD9-CM codes 290 and 331)• depression/psychosis (ICD9-CM codes 295-299 and 311)• neurotic disorder (ICD9-CM codes 300-309)• osteoporosis (ICD9-CM code 733)• cerebrovascular disease (ICD9-CM codes 430-438)• hypertension (ICD9-CM codes 401-405)• cardiovascular disease (ICD9-CM codes 410-414 and 420-429)• diabetes (ICD9-CM code 250)• cancer (ICD9-CM codes 140-239)• gait or balance disorders (ICD9-CM codes 333-334, 342, 359, 365-

366,369, 458, 721)• any previous injury diagnosis (ICD9-CM codes 800-999)

27

• Methods (cont.)– Blue Cross Medication Categories

• Antihistamines• Narcotic Pain Killers• NSAIDS• Anti-convulsants• Anti-depressants• Anti-psychotics• Anxiolytics, sedatives, hypnotics• Anti-Parkinson’s/Movement Disorder Agents• Electrolytic, Caloric, Water Balance• Visual Impairment• Anti-ulcer Agents• Corticosteriods• Sex Hormones• Diabetes Agents• Thyroid Medication• Anti-coagulants• Blood Pressure Agents

28

• Methods (cont.)– Analysis

• Cases were matched 1:5 on age, health region and index injury date

• For a 1 year period prior to the injury date, all medical co-morbidity and medication purchases were tabulated for each case and control

• Medication use was divided by 4 time periods of use prior to injury: a) 0-30 days, b) 31-90 days, c) 91-180 days, d) 191-385 days.

• Conditional logistic regression used for unadjusted and adjusted models.

29

• Results– For the 3-year study period, a total of 282 individuals were

identified as having sustained a farm related injury

– Of the 282 cases, 39 (13.8%) were hospitalized.

– Ninety-seven (34%) were related to machinery, 55 (20%) were related to animals, 35 (12%) were related to falls, 27 (10%) were struck by an object, 24 (9%) were caught between objects, and 44 (15%) were distributed among other miscellaneous mechanisms.

– The mean age of cases was 71.4 years (sd5.0) and controls 71.8 (sd4.6).

30

• Results (cont.)– Cases had been treated significantly more often

for: incontinence/urinary tract problems (4.6%vs.2.2%), osteoarthritis (23.4%vs.16.2%), osteoporosis (2.1%vs.0.5%), and previous injury (30.5%vs.23.6%).

– Cases had been prescribed significantly more narcotic pain killers (25.2%vs.15.0%), non-steroidal anti-inflammatories (NSAIDs) (36.2%vs.24.4%), and significantly fewer anti-convulsants (0.0%vs.1.8%).

31

Table: Unadjusted and adjusted odds-ratios relating morbidity and medication to farm injury (Only variables achieving significance are shown)

Variable Unadjusted Odds Ratio Adjusted Odds Ratio

Morbidity

Incontinence/Urinary Tract Disorders 2.15(1.11,4.18) 2.95(1.30,6.71)

Osteoarthritis 1.57(1.15,2.14) 1.16(0.78,1.71)

Osteoporosis 4.29(1.44,12.75) 3.46(0.98,12,18)

Previous Injury Trauma 1.41(1.06,1.88) 1.42(1.04,1.95)

Medication Use

Narcotic Pain Killers No use of medication 0-30 days prior to injury date >30 days prior to injury date >90 days prior to injury date >180 days prior to injury date

1.001.00(0.46,2.17)8.14(4.74,14.00)1.15(4.74,14.00)0.82(0.44,1.50)

1.000.68(0.28,1.63)9.37(4.95,17.72)1.03(0.44,2.38)0.63(0.32,1.24)

NSAIDS No use of medication 0-30 days prior to injury date >30 days prior to injury date >90 days prior to injury date >180 days prior to injury date

1.001.44(0.85,2.43)2.41(1.56,3.72)1.25(0.72,2.15)1.62(1.03,2.54)

1.001.56(0.80,3.03)2.40(1.43,4.03)0.95(0.51,1.84)1.67(1.00,2.81)

Anxiolytics, sedatives, hypnotics No use of medication 0-30 days prior to injury date >30 days prior to injury date >90 days prior to injury date >180 days prior to injury date

1.001.92(1.06,3.47)1.18(0.53,2.61)0.85(0.29,2.50)0.53(0.19,1.51)

1.003.01(1.39,6.52)0.83(0.31,2.20)0.49(0.14,1.75)0.34(0.10,1.16)

32

• Discussion– Limitations

• No actual measure of medication consumption.– Purchase of medication as a proxy for medication use.

• No measure of over-counter remedies, alcohol, or other drug use.

• If co-morbidity is not diagnosed, it does not mean that it does not exist.

33

• Discussion (cont.)– Strengths

• Population based approach was used to examine the relationship between medication use and injury.

• Linkage of the different government databases was successful in identifying a group of farmers where cases and controls could be chosen with the assumption of equivalent exposure.

• All medication and co-morbidity data taken from the same uniform system. Little chance of systematic bias.

34

• Discussion (cont.)– Main Relationships

• The use of sedative class drugs and injury observed.

• Incontinence/urinary tract disorders also related to injury

• Strong relationship between the recent use of narcotic pain killers and injury observed.

• Weaker but significant relationship between the recent use of NSAIDS and injury

35

• Discussion (cont.)– Explanation

• Distraction may be related to injury in this active working older population

– Prostate problems related to injury

– Pain as well when medication ceased

• Guarding due to pain - Limits in reaction time and mobility may be related to subsequent injury

• Premature return to work (de-conditioning)

• Possible effects of withdrawal from narcotic use.

36

Recommendations

• Muscular-skeletal issues, injury and arthritis– Return to work should be phased in over a re-

conditioning period– Do not stop pain or anti-inflammatory medication

prematurely

• Hearing– Preserve hearing – PHP and environmental

modifications– Use hearing aids to maintain sensory awareness

37

Recomendations• Benzodiazepines/Sleep

– New medications available• “Z-drugs (zaleplon, zolpidem, zopliclone)

– Shorter elimination time– Less dependence– Less tolerance (escalating dosage)

– Non-pharmacological Strategies• Regular bedtime• Avoid caffeine and alcohol• Exercise• Napping less than 30 minutes• Sleep area dark and quiet

38

Recommendations• Polypharmacy

– Increase awareness of physicians, nurses and pharmacists in rural areas to educate/alert farmers about potential problems

– Monitor medication strength• Eg: anti-hypertensives

• Regular check-ups/screening– Deal with prostate issues etc.

39

10 Most Common Physician Diagnoses for Farm Residents

• Back Pain• Hypertension• Unspecified symptoms• Lumbar sprain/strain• Cervical deformity• Routine exam• Upper respiratory tract infections• Acute pharyngitis• Thoracic sprain/strain• Depressive disorder

40

THANK YOUTHANK YOU