Of 83 eligible patients, 75 were recruited into the study. At baseline, the average age was 67.1 years, 59% (n=44) were female, and the average vision in the better eye was logMAR 0.85, or approximately 20/150 (see Table 1). Following multiple attempts to contact all participants at both time points, 69% (n=52) of the original cohort completed the survey four months postoperatively, and 41% (n=31) completed the survey eight months post-operatively.
Baseline characteristics of the cohort population and those reached for four-month follow-up were compared to explore response bias associated with age, gender, or socioeconomic status (see Table 1).
Table 1. Baseline characteristics of the total cohort as compared to baseline characteristics of participants surveyed at four months
|
Baseline (n=75)
|
4 months (n=52)
|
p
|
|
Mean
|
SD
|
Mean
|
SD
|
t-test
|
Age
|
67.1
|
12.0
|
66.6
|
13.1
|
0.82
|
Simple Poverty Scorecard
|
54.5
|
12.7
|
55.8
|
13.4
|
0.57
|
|
% Female
|
% Female
|
X2 test
|
Gender
|
59%
|
62%
|
0.45
|
Baseline metrics for the complete case analysis by gender are in Table 2. Scores on the Simple Poverty Scorecard (SPSC) at baseline ranged from 28 to 83, with a mean score of 55.8. This translates to a 50.6% likelihood that an individual falls beneath the poverty line. More woman than men reported an income that fell below the poverty line (87% v 65%, p=0.05.) Scores on the PHQ-9 depression screening tool at baseline ranged from 0 to 17 out of a possible 27. The mean score was 6.1, which indicates mild depression. Six individuals had scores indicating moderate depression, and no scores indicated severe depression. Thirteen participants (25%) said that their symptoms of depression made life either very or extremely difficult. Scores on the GAD-7 anxiety screening tool at baseline ranged from 0 to 13 out of a possible 21. The mean score was 3.2, which indicates minimal anxiety. Five participants had scores indicating moderate anxiety, and no scores indicated severe anxiety. Ten participants (19%) said that their symptoms of anxiety made life either very or extremely difficult.
Table 2. Baseline of all metrics by sex.
|
Total
(n=52)
|
Females
(n=32)
|
Males
(n=20)
|
t-test
|
|
Mean
|
SD
|
Mean
|
SD
|
Mean
|
SD
|
p
|
Age
|
66.6
|
13.1
|
65.0
|
14.8
|
69.0
|
9.7
|
0.30
|
Log MAR VA in Better eye
|
0.80
|
0.67
|
0.78
|
0.67
|
0.84 (n=19)
|
0.69
|
0.76
|
Simple Poverty Score
|
55.8
|
13.4
|
54.3
|
13.4
|
58.4
|
13.0
|
0.29
|
Income Group
|
1.81
|
1.1
|
1.66
|
1.0
|
2.05
|
1.2
|
0.21
|
PHQ
|
6.1
|
4.2
|
6.3
|
3.8
|
5.8
|
4.9
|
0.65
|
GAD
|
3.2
|
3.0
|
2.8
|
2.8
|
3.8
|
3.3
|
0.27
|
|
|
|
|
X2 test
|
Work outside the home for pay
|
17% (n=9)
|
16% (n=5)
|
20% (n=4)
|
0.69
|
Income below poverty line
|
79%(n=41)
|
87% (n=28)
|
65% (n=13)
|
0.05
|
Vision interfering with ability to work
|
88% (n=46)
|
88% (n=28)
|
90% (n=18)
|
0.78
|
Table 3 summarizes the differences in 7 outcomes at baseline and four months after cataract surgery, and Table 4 summarizes the same 7 outcomes stratified by sex. Tables 5 and 6 summarize the regression analyses when the relationships were controlled for age and sex.
Table 3. Comparison of baseline and outcomes at four months (n=52)
|
Baseline
|
4 Month Follow-up
|
Paired t-test
|
|
Mean
|
SD
|
Mean
|
SD
|
p
|
Simple Poverty Scorecard
|
55.8
|
12.7
|
56.1
|
15.5
|
0.92
|
Income Group
|
1.81
|
1.1
|
2.53
|
1.1
|
<0.005
|
PHQ
|
6.1
|
4.2
|
6.0
|
6.1
|
0.87
|
GAD
|
3.2
|
3.0
|
5.6
|
6.1
|
<0.005
|
|
|
|
McNemar’s Test
|
Work outside the home for pay
|
17% (n=12)
|
37% (n=19)
|
0.03
|
Income below poverty line
|
79%(n=41)
|
56% (n=29)
|
0.02
|
Vision interfering with ability to work
|
88% (n=46)
|
75% (n=39)
|
0.14
|
Table 4. Comparison of baseline and outcomes at 4 months by sex. (n=52)
|
Baseline
|
4 month Follow Up
|
|
Females
(n=32)
|
Males
(n=20)
|
t-test
|
Females
n=32
|
Paired t-test
|
Males
n=20
|
Paired t-test
|
|
Mean
|
SD
|
Mean
|
SD
|
p
|
Mean
|
p
|
Mean
|
p
|
Simple Poverty Scorecard
|
54.3
|
13.6
|
58.3
|
13.0
|
0.29
|
53.2
|
0.51
|
60.8
|
0.70
|
Income Group
|
1.66
|
1.0
|
2.11
|
1.2
|
0.21
|
2.53
|
0.001
|
2.53
|
0.13
|
PHQ
|
6.3
|
3.8
|
5.8
|
4.9
|
0.65
|
7.3
|
0.43
|
3.8
|
0.14
|
GAD
|
2.8
|
2.8
|
3.8
|
3.3
|
0.27
|
6.0
|
0.004
|
5.1
|
0.38
|
|
|
|
X2 test
|
|
McNemar’s test
|
|
McNemar’s test
|
Work outside the home for pay
|
16% (n=5)
|
20% (n=4)
|
0.69
|
25% (n=8)
|
0.51
|
55% (n=11)
|
0.04
|
Income below poverty line
|
88% (n=28)
|
65% (n=13)
|
0.05
|
53% (n=17)
|
0.01
|
60% (n=12)
|
0.99
|
Vision interfering with ability to work
|
88% (n=28)
|
90% (n=18)
|
0.78
|
75% (n=24)
|
0.34
|
75% (n=15)
|
0.45
|
Table 5. Effect of Cataract Surgery - Linear Regression Models
|
ß
|
95% CI
|
p
|
Simple Poverty Score
|
0.23
|
-4.12, 4.58
|
0.92
|
Income Group
|
0.69
|
0.33, 1.05
|
<0.001
|
PHQ
|
-0.15
|
-1.97, 1.66
|
0.87
|
GAD
|
2.42
|
0.82, 4.03
|
0.003
|
- Mixed effects linear regression controlled for age and sex.
Table 6. Effect of Cataract Surgery - Logistic Regression Models
|
OR
|
95% CI
|
p
|
Work outside the home for pay
|
3.47
|
1.15, 10.48
|
0.027
|
Personal income below poverty line
|
0.30
|
0.11, 0.80
|
0.016
|
Vision interfering with ability to work
|
0.39
|
0.13, 1.12
|
0.090
|
- Mixed effects logistic regression controlled for age and sex.
The SPSC values did not change significantly in the full cohort at the four-month follow-up, and analysis by gender and multivariate analysis did not reveal any differences. Mean income group increased significantly among all participants (1.81 to 2.53, p<0.005), but analysis by gender indicated that the increase was statistically significant only among females (1.66 to 2.53, p=0.001 vs 2.11 to 2.53 p=0.13). The effect remained statistically significant on multivariate analysis (ß=0.69, p<0.001). The proportion of participants who reported income below the poverty line decreased significantly among the whole cohort (79% to 56%, p=0.02). More women than men at baseline reported income below the poverty line (88% v 65%, p=0.05), and the change in the proportion reporting income below the poverty line was significant only among females (88% to 53% p=0.01 v 65% to 60%, p=0.99). Multivariate analysis indicated that the odds of reporting income below the poverty line dropped by more than two thirds following cataract surgery (OR=0.030, p=0.016.) The proportion of participants working outside the home for pay increased from 17% to 37% (p=0.03) among the whole cohort, but when analyzed by gender, only men showed a statistically significant increase (20% to 55% p=0.04 vs 16% to 25%, p=0.51.) When controlled for age and gender, the effect remained statsitcially significant, indicating that cataract surgery increased the odds that an individual would be working outside the home for pay by almost 3.5 times (OR=3.47, p=0.027.) A majority of patients reported that vision interfered with their ability to work at baseline (88%), and that proportion did not change significantly at four-month follow-up among the whole cohort (75%, p=0.14). Analysis by gender and multivariate analysis controlling for age and gender did not reveal any effect.
Anxiety scores increased significantly among the whole cohort (3.2 to 5.6, p=0.005) indicating a change from ‘minimal anxiety’ to ‘mild anxiety’, and both genders showed an increase in anxiety with the effect being statistically significant among women (2.8 to 6.0, p=0.005 v. 3.8 to 5.1, p=0.38.) Multivariate analysis showed a mean increase of 2.42 points (p=0.003) following surgery. The number of participants who reported that their symptoms of anxiety made life difficult or extremely difficult fell from 19%(n=10) to 12% (n=6). Depression scores for the whole cohort, when analyzed by gender and on multivariate analysis did not change between baseline and follow-up. The number of participants who reported that their symptoms of depression made life difficult or extremely difficult fell from 25%(n=13) to 12% (n=6).