A cost-benefit analysis of the life-prolonging effect of nonsteroidal anti-inflammatory drugs for persons with dementia and pain

Figures & data

Table 1. Definitions of all the variables.

Variable	Description
Mortality π	Subject is known to be deceased. 1 = Deceased; 0 = not deceased, or unknown to be deceased.
Dementia D	Clinical Dementia Rating (CDR) Sum of Boxes (SB). Total CDR score based on Memory, Orientation, Judgement & Problem Solving, Community Affairs, Home & Hobbies, Personal Care, each of the six categories on a scale of 0 to 3.
NSAID	Reported current use of nonsteroidal anti-inflammatory medication. 1= Reported use at visit; 0 = Did not report use at visit.
Aspirin	Reported use of Aspirin. 1 = Reported use of Aspirin at any visit; 0 = Did not report use at any visit.
Ibuprofen	Reported use of Ibuprofen. 1 = Reported use of Ibuprofen at any visit; 0 = Did not report use at any visit.
Naproxen	Reported use of Naproxen. 1 = Reported use of Naproxen at any visit; 0 = Did not report use at any visit.
Acetaminophen	Reported use of Acetaminophen. 1 = Reported use of Acetaminophen at any visit; 0 = Did not report use at any visit.
Corrective lenses	If the subject usually wears corrective lenses, is the subject’s vision functionally normal with corrective lenses? 1 = Yes; 0 = No, if any functional impairment exists (reduced ability to do everyday activities such as reading, watching television).
Medicare eligibility	Is the subject eligible for Medicare? Age ≥ 65 = 1; Age < 65 = 0.
Nursing Homes	Is the subject’s type of residence a skilled nursing facility/nursing home? 1 = Yes; 0 = No.
Antipsychotics	Reported current use of an antipsychotic agent. 1= Reported use at visit; 0 = Did not report use at visit.
Beta-Blockers	Reported current use of a beta-adrenergic blocking agent. 1= Reported use at visit; 0 = Did not report use at visit.
FDA-Approved Medications	Reported current use of an FDA-approved medication for Alzheimer’s disease symptoms. 1= Reported use at visit; 0 = Did not report use at visit.
Age	Subjects age at time of visit.
White	NIH race definition. 1 = White; 0 = Non-White.
Female	Subject’s sex. Female = 1; Male = 0.
Height	Subject’s height in inches.
Birth month	Month the person was born. 1 = Born between October and December; 0 = Not born between October and December.
BMI	Body Mass Index. The standardized calculation used is: BMI = weight (lbs) ÷ [height (in)]^2 × 703.
Smoker years	Total number of years smoked cigarettes.
QoL	1 - [Total Geriatric Depression Scale (GDS) score/15].
Community living	Does the subject reside in a retirement community or independent group living? 1 = Yes; 0 = No.
Assisted living	Does the subject reside in assisted living/boarding home/adult family home? 1 = Yes; 0 = No.

Table 2. Descriptive statistics for all the variables.

Variable	Number	Mean	Standard Deviation	Minimum	Maximum
Mortality π	33,794	0.2599	0.4386	0	1
Dementia	33,794	3.7448	3.4847	0.5	18
NSAID	33,794	0.4374	0.4961	0	1
Aspirin	32,816	0.1769	0.3816	0	1
Ibuprofen	32,816	0.0271	0.1624	0	1
Naproxen	32,816	0.0352	0.1843	0	1
Acetaminophen	32,816	0.0378	0.1908	0	1
Corrective lenses	33,794	0.9430	0.2318	0	1
Medicare eligibility	33,794	0.8682	0.3282	0	1
Nursing homes	33,794	0.0061	0.0777	0	1
Antipsychotics	33,794	0.0445	0.2063	0	1
Beta-Blockers	33,794	0.2331	0.4228	0	1
FDA-Approved Medications	33,794	0.4676	0.4990	0	1
Age	33,794	75.4171	9.5714	21	107
White	33,794	0.8384	0.3681	0	1
Female	33,794	0.4954	0.5000	0	1
Height	33,794	65.7053	4.1536	37	82
Birth month	33,794	0.2512	0.4337	0	1
BMI	33,794	26.7881	4.9466	12.1	84.2
Smoker years	33,794	10.9138	15.7073	0	82
QoL	33,794	0.8289	0.1816	0	1
Community Living	33,794	0.0682	0.2522	0	1
Assisted Living	33,794	0.0304	0.1718	0	1

Table 3. Marginal effects estimates for random effects models of pain relievers on mortality using logit (p-values in parentheses).^†

Variables	(1)	(2)	(3)	(4)	(5)
Main Variables
Dementia	0.0119*** (0.000)	0.0183*** (0.000)	0.0021*** (0.000)	0.0129*** (0.000)	0.0152*** (0.001)
NSAID α1	−0.0135*** (0.000)
Aspirin		−0.0214*** (0.003)
Ibuprofen			−0.0042** (0.031)
Naproxen				−0.0028 (0.777)
Acetaminophen					0.0084 (0.255)
Non-pharmaceutical Controls
Vision correction	−0.0161*** (0.007)	−0.0307*** (0.011)	−0.0055*** (0.001)	−0.0120* (0.071)	−0.0218*** (0.008)
Medicare eligibility	−0.0713*** (0.000)	−0.0950*** (0.000)	−0.0151*** (0.000)	−0.0704*** (0.000)	−0.0826*** (0.000)
Nursing Homes	0.0738** (0.040)	0.1243*** (0.000)	0.0303*** (0.000)	0.0891*** (0.005)	0.1090*** (0.000)
Pharmaceutical Controls
Antipsychotics	0.0154* (0.068)	0.0281** (0.042)	0.0040** (0.051)	0.0230** (0.051)	0.0150 (0.171)
Beta Blockers	0.0119*** (0.005)	0.0178** (0.038)	0.0013 (0.123)	0.0132*** (0.007)	0.0137** (0.023)
FDA-Approved Medications	0.0210*** (0.000)	0.0217*** (0.009)	0.0020** (0.024)	0.0278*** (0.000)	0.0276** (0.023)
Health Controls
Age	0.0082*** (0.000)	0.0112*** (0.000)	0.0012*** (0.000)	0.0091*** (0.000)	0.0101*** (0.000)
White	0.0938*** (0.000)	0.1091*** (0.000)	0.0087*** (0.000)	0.1083*** (0.000)	0.1014*** (0.000)
Female	−0.0553*** (0.000)	−0.0623*** (0.000)	−0.0071*** (0.000)	−0.0492*** (0.000)	−0.0625*** (0.000)
Height	0.0016** (0.036)	0.0022 (0.171)	0.0032** (0.034)	0.0021* (0.058)	0.0014 (0.189)
Birth month	−0.0085 (0.150)	−0.0033 (0.782)	−0.0016 (0.108)	−0.0023 (0.732)	−0.0017 (0.832)
BMI	−0.0025*** (0.000)	−0.0032*** (0.001)	−0.0003*** (0.001)	−0.0021*** (0.002)	−0.0027*** (0.000)
Smoker	0.0009*** (0.000)	0.0010*** (0.001)	0.0001*** (0.001)	0.0011*** (0.000)	0.0011*** (0.000)
QOL	−0.0390*** (0.000)	−0.0479** (0.033)	−0.0088*** (0.000)	−0.0514*** (0.000)	−0.0536*** (0.000)
Community Living	0.0418*** (0.000)	0.0584*** (0.000)	0.0091*** (0.000)	0.0521*** (0.000)	0.0526*** (0.000)
Assisted Living	0.0583*** (0.000)	0.0906*** (0.000)	0.0272*** (0.000)	0.0698*** (0.000)	0.0826*** (0.000)
Number of Obs.	33,794	13,624	29,636	27,070	20,470
Number of Individuals	16,526	7,606	14,844	13,734	10,835
Chi-Square^††	16,000*** (0.000)	5,472*** (0.000)	13,000*** (0.000)	12,000*** (0.000)	8,758*** (0.000)

^† Significance levels on coefficients: * 10%; ** 5%; *** 1%.

^††The Chi-square is for a likelihood-ratio test that ρ = 0, which implies that there would be no difference between using a pooled sample rather than a panel for estimation.

^†††All equations also include 11 of the 12 visit numbers.

Table 4. Average treatment effects of pain relievers on mortality using logit for propensity score matching (p-values in parentheses).^†

Variables	(1)	(2)	(3)	(4)	(5)
NSAID: α1	−0.0455*** (0.000)
Aspirin		−0.0380*** (0.000)
Ibuprofen			−0.0579*** (0.000)
Naproxen				−0.0252 (0.140)
Acetaminophen					0.0054 (0.711)
Obs. Raw Obs. Matched	33,794 67,588	13,624 27,248	29,636 59,272	27,070 54,140	20,470 40,940

^† Significance levels on coefficients: *10%; **5%; ***1%.

Table 5. Cost-benefit analysis of six interventions compared with NSAID.

Variables	Mortality Rate	QALYs Changed	Benefits	Costs	Net-Benefits
NSAID	˗ 0.0135	0.2241	36,640	11,063	25,577
Antipsychotics	0.0154	˗ 0.2556	˗ 41797	62,852	˗ 104,649
Beta-Blockers	0.0119	˗ 0.1975	˗ 32298	797	˗ 33095
FDA-Approved Medications	0.0210	˗ 0.3486	˗ 56996	31,949	˗ 88945
Vision Correction	˗ 0.0161	0.2673	43,697	765	42,932
Medicare Eligibility	˗ 0.0713	1.1836	193,515	17,444	176,071
Avoiding Nursing Homes	˗ 0.0738	1.2251	200,301	54,245	146,056